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" <[e-mail]>
Acked-by: Arnd Bergmann <[e-mail]>
Acked-by: Michał Mirosław <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/misc/cb710/sgbuf2.c

···
 /**
  * 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@