misc: cb710: sgbuf2: Add missing documentation for cb710_sg_dwiter_write_next_block...

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.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>