On at91sam9260 and at91sam9g20 the SRAM banks are mirrored. We can
merge them together to be able to have bigger and continuous
internal RAM.
Signed-off-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>