nand/denali: Document CONFIG symbols

The patch "nand/denali: Adding Denali NAND driver support"
introduced two config symbols without documenting them.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Cc: Chin Liang See <clsee@altera.com>
Cc: Masahiro Yamada <yamada.m@jp.panasonic.com>
1 file changed