[PATCH] mbxfb: add more registers to debugfs

This patch fixes debugfs for mbxfb and adds some missing registers.

The way registers were read was out of sync with the rest of the driver (direct
access instead of using readl())

sdram controller registers are now accessible in the sdram/ subdirectory and
some other registers are grouped in the misc/ subdirectory.
Signed-off-by: Raphael Assenat <raph@8d.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Acked-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>