misc: cb710: sgbuf2: Add missing documentation for cb710_sg_dwiter_write_next_block()'s 'data' arg

An attempt was made to provide a proper kerneldoc header for
cb710_sg_dwiter_write_next_block(), but a description for it's 'data'
argument was missed.

Squashes W=1 kernel build warning:

 drivers/misc/cb710/sgbuf2.c:131: warning: Function parameter or member 'data' not described in 'cb710_sg_dwiter_write_next_block'

Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200626130525.389469-9-lee.jones@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/cb710/sgbuf2.c

@@ -117,6 +117,7 @@ static void sg_dwiter_write_slow(struct sg_mapping_iter *miter, uint32_t data)
 /**
  * cb710_sg_dwiter_write_next_block() - write next 32-bit word to sg buffer
  * @miter: sg mapping iterator used for writing
+ * @data: data to write to sg buffer
  *
  * Description:
  *   Writes 32-bit word starting at byte pointed to by @miter@