ARM: mmp: add sram allocator

On mmp platform, there have two sram banks:
audio sram and internal sram. The audio sram is mainly for audio;
the internal sram is for video, wtm and power management.
So add the sram allocator using genalloc to manage them.

Every sram bank will register its own platform device
info, after the sram allocator create the generic pool
for the sram bank, the user module can use the pool's
name to get the pool handler; then it can use the handler
to alloc/free memory with genalloc APIs.

Signed-off-by: Leo Yan <leoy@marvell.com>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 3146ed3..f03ccae 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -558,6 +558,7 @@
 	select TICK_ONESHOT
 	select PLAT_PXA
 	select SPARSE_IRQ
+	select GENERIC_ALLOCATOR
 	help
 	  Support for Marvell's PXA168/PXA910(MMP) and MMP2 processor line.