[ARM] 4085/1: AT91: Header fixes.

Fix two typo's where AT01_* was used instead of AT91_*.
[Patch from Wojtek Kaniewski]

Fix definition of AT91_SMC_EXNWMODE for the SAM9 processors.
[Patch from Wu Xuan]

Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>