[ARM] pxa: introduce plat-pxa for PXA common code and add DMA support

1. introduce folder of 'arch/arm/plat-pxa' for common code across different
   PXA processor families

2. initially moved DMA code into plat-pxa

3. common code in <mach/dma.h> moved into <plat/dma.h>, new processors
   should implement its own <mach/dma.h>, provide the following required
   definitions and '#include <plat/dma.h>' in the end:

   - DMAC_REGS_VIRT for mapped virtual address of the DMA registers'
     physical I/O memory

Signed-off-by: Eric Miao <eric.miao@marvell.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 12abdd43201f..5ba00358e805 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -481,6 +481,7 @@ config ARCH_PXA
         select GENERIC_TIME
         select GENERIC_CLOCKEVENTS
         select TICK_ONESHOT
+        select PLAT_PXA
         help
           Support for Intel/Marvell's PXA2xx/PXA3xx processor line.
 
@@ -618,6 +619,7 @@ source "arch/arm/mach-loki/Kconfig"
 source "arch/arm/mach-mv78xx0/Kconfig"
 
 source "arch/arm/mach-pxa/Kconfig"
+source "arch/arm/plat-pxa/Kconfig"
 
 source "arch/arm/mach-sa1100/Kconfig"
 
@@ -687,6 +689,9 @@ config PLAT_IOP
 config PLAT_ORION
         bool
 
+config PLAT_PXA
+        bool
+
 source arch/arm/mm/Kconfig
 
 config IWMMXT