ARM: mmp: remove remaining legacy pxa-dma support

All drivers have stopped using this code, so we can just
as well stop initializing it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/plat-pxa/Makefile

@@ -2,7 +2,7 @@
 # Makefile for code common across different PXA processor families
 #
 
-obj-y	:= dma.o
+obj-$(CONFIG_ARCH_PXA)		:= dma.o
 
 obj-$(CONFIG_PXA3xx)		+= mfp.o
 obj-$(CONFIG_ARCH_MMP)		+= mfp.o