DA830 EVM: use DA8XX_AEMIF_*_BASE #define's

The board file #define's its own version of EMIFA base addresses, while there
are DA8XX_AEMIF_*_BASE macros #define'd in <mach/da8xx.h>.  Start using them
instead.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>