ARM: OMAP4/5: Make OMAPx_SRAM_SCRATCH_ defines common

These defines are same across OMAP4/5. So move them to
omap_common.h. This is required for the patches that
follow.

Signed-off-by: Sricharan R <r.sricharan@ti.com>
diff --git a/arch/arm/cpu/armv7/omap5/emif.c b/arch/arm/cpu/armv7/omap5/emif.c
index 3f37abd..b4c1319 100644
--- a/arch/arm/cpu/armv7/omap5/emif.c
+++ b/arch/arm/cpu/armv7/omap5/emif.c
@@ -32,8 +32,8 @@
 
 #ifndef CONFIG_SYS_EMIF_PRECALCULATED_TIMING_REGS
 #define print_timing_reg(reg) debug(#reg" - 0x%08x\n", (reg))
-static u32 *const T_num = (u32 *)OMAP5_SRAM_SCRATCH_EMIF_T_NUM;
-static u32 *const T_den = (u32 *)OMAP5_SRAM_SCRATCH_EMIF_T_DEN;
+static u32 *const T_num = (u32 *)OMAP_SRAM_SCRATCH_EMIF_T_NUM;
+static u32 *const T_den = (u32 *)OMAP_SRAM_SCRATCH_EMIF_T_DEN;
 #endif
 
 #ifdef CONFIG_SYS_DEFAULT_LPDDR2_TIMINGS