mtd: rawnand: omap_elm: Finish half populated function header, demote empty ones

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

 drivers/mtd/nand/raw/omap_elm.c:102: warning: Function parameter or member 'ecc_steps' not described in 'elm_config'
 drivers/mtd/nand/raw/omap_elm.c:102: warning: Function parameter or member 'ecc_step_size' not described in 'elm_config'
 drivers/mtd/nand/raw/omap_elm.c:102: warning: Function parameter or member 'ecc_syndrome_size' not described in 'elm_config'
 drivers/mtd/nand/raw/omap_elm.c:440: warning: Function parameter or member 'info' not described in 'elm_context_save'
 drivers/mtd/nand/raw/omap_elm.c:488: warning: Function parameter or member 'info' not described in 'elm_context_restore'

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
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20201109182206.3037326-19-lee.jones@linaro.org

drivers/mtd/nand/raw/omap_elm.c

@@ -96,6 +96,9 @@ static u32 elm_read_reg(struct elm_info *info, int offset)
  * elm_config - Configure ELM module
  * @dev:	ELM device
  * @bch_type:	Type of BCH ecc
+ * @ecc_steps:	ECC steps to assign to config
+ * @ecc_step_size:	ECC step size to assign to config
+ * @ecc_syndrome_size:	ECC syndrome size to assign to config
  */
 int elm_config(struct device *dev, enum bch_ecc bch_type,
 	int ecc_steps, int ecc_step_size, int ecc_syndrome_size)
@@ -432,7 +435,7 @@ static int elm_remove(struct platform_device *pdev)
 }
 
 #ifdef CONFIG_PM_SLEEP
-/**
+/*
  * elm_context_save
  * saves ELM configurations to preserve them across Hardware powered-down
  */
@@ -480,7 +483,7 @@ static int elm_context_save(struct elm_info *info)
 	return 0;
 }
 
-/**
+/*
  * elm_context_restore
  * writes configurations saved duing power-down back into ELM registers
  */