mtd: rawnand: brcmnand: Demote non-conformant kernel-doc headers

Fixes the following W=1 kernel build warning(s):

 drivers/mtd/nand/raw/brcmnand/brcmnand.c:1854: warning: Function parameter or member 'host' not described in 'brcmnand_edu_trans'
 drivers/mtd/nand/raw/brcmnand/brcmnand.c:1854: warning: Function parameter or member 'addr' not described in 'brcmnand_edu_trans'
 drivers/mtd/nand/raw/brcmnand/brcmnand.c:1854: warning: Function parameter or member 'buf' not described in 'brcmnand_edu_trans'
 drivers/mtd/nand/raw/brcmnand/brcmnand.c:1854: warning: Function parameter or member 'len' not described in 'brcmnand_edu_trans'
 drivers/mtd/nand/raw/brcmnand/brcmnand.c:1854: warning: Function parameter or member 'cmd' not described in 'brcmnand_edu_trans'
 drivers/mtd/nand/raw/brcmnand/brcmnand.c:1951: warning: Function parameter or member 'host' not described in 'brcmnand_fill_dma_desc'
 drivers/mtd/nand/raw/brcmnand/brcmnand.c:1951: warning: Function parameter or member 'desc' not described in 'brcmnand_fill_dma_desc'
 drivers/mtd/nand/raw/brcmnand/brcmnand.c:1951: warning: Function parameter or member 'addr' not described in 'brcmnand_fill_dma_desc'
 drivers/mtd/nand/raw/brcmnand/brcmnand.c:1951: warning: Function parameter or member 'buf' not described in 'brcmnand_fill_dma_desc'
 drivers/mtd/nand/raw/brcmnand/brcmnand.c:1951: warning: Function parameter or member 'len' not described in 'brcmnand_fill_dma_desc'
 drivers/mtd/nand/raw/brcmnand/brcmnand.c:1951: warning: Function parameter or member 'dma_cmd' not described in 'brcmnand_fill_dma_desc'
 drivers/mtd/nand/raw/brcmnand/brcmnand.c:1951: warning: Function parameter or member 'begin' not described in 'brcmnand_fill_dma_desc'
 drivers/mtd/nand/raw/brcmnand/brcmnand.c:1951: warning: Function parameter or member 'end' not described in 'brcmnand_fill_dma_desc'
 drivers/mtd/nand/raw/brcmnand/brcmnand.c:1951: warning: Function parameter or member 'next_desc' not described in 'brcmnand_fill_dma_desc'
 drivers/mtd/nand/raw/brcmnand/brcmnand.c:1977: warning: Function parameter or member 'host' not described in 'brcmnand_dma_run'
 drivers/mtd/nand/raw/brcmnand/brcmnand.c:1977: warning: Function parameter or member 'desc' not described in 'brcmnand_dma_run'

Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Kamal Dasu <kdasu.kdev@gmail.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Cc: linux-mtd@lists.infradead.org
Cc: bcm-kernel-feedback-list@broadcom.com
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20201109182206.3037326-14-lee.jones@linaro.org

drivers/mtd/nand/raw/brcmnand/brcmnand.c

@@ -1846,7 +1846,7 @@ static void brcmnand_write_buf(struct nand_chip *chip, const uint8_t *buf,
 	}
 }
 
-/**
+/*
  *  Kick EDU engine
  */
 static int brcmnand_edu_trans(struct brcmnand_host *host, u64 addr, u32 *buf,
@@ -1937,7 +1937,7 @@ static int brcmnand_edu_trans(struct brcmnand_host *host, u64 addr, u32 *buf,
 	return ret;
 }
 
-/**
+/*
  * Construct a FLASH_DMA descriptor as part of a linked list. You must know the
  * following ahead of time:
  *  - Is this descriptor the beginning or end of a linked list?
@@ -1970,7 +1970,7 @@ static int brcmnand_fill_dma_desc(struct brcmnand_host *host,
 	return 0;
 }
 
-/**
+/*
  * Kick the FLASH_DMA engine, with a given DMA descriptor
  */
 static void brcmnand_dma_run(struct brcmnand_host *host, dma_addr_t desc)