mxc: add cscr register defintions

This adds macros to get CSCR upper, lower and additional registers.
These registers are needed to configure a chip select line. The offset
layouts of these Registers are identical on mx27 and mx31, hence we can
use the macros in generic way

Signed-off-by: Luotao Fu <l.fu@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

arch/arm/plat-mxc/include/mach/mxc.h

@@ -33,4 +33,10 @@
 # define cpu_is_mx27() (0)
 #endif
 
+#if defined(CONFIG_ARCH_MX3) || defined(CONFIG_ARCH_MX2)
+#define CSCR_U(n) (IO_ADDRESS(WEIM_BASE_ADDR) + n * 0x10)
+#define CSCR_L(n) (IO_ADDRESS(WEIM_BASE_ADDR) + n * 0x10 + 0x4)
+#define CSCR_A(n) (IO_ADDRESS(WEIM_BASE_ADDR) + n * 0x10 + 0x8)
+#endif
+
 #endif /*  __ASM_ARCH_MXC_H__ */