omap: add basic SPL support

- Provide alternate implementations of board_init_f()
  board_init_r() for OMAP spl.
- Provide linker script
- Initialize global data
- Add serial console support
- Update CONFIG_SYS_TEXT_BASE to allow for SPL's bss and move
  it to board config header from config.mk

Signed-off-by: Aneesh V <aneesh@ti.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>
diff --git a/arch/arm/cpu/armv7/Makefile b/arch/arm/cpu/armv7/Makefile
index 299792a..92a5a96 100644
--- a/arch/arm/cpu/armv7/Makefile
+++ b/arch/arm/cpu/armv7/Makefile
@@ -26,7 +26,12 @@
 LIB	= $(obj)lib$(CPU).o
 
 START	:= start.o
-COBJS	:= cpu.o cache_v7.o
+
+ifndef CONFIG_SPL_BUILD
+COBJS	+= cache_v7.o
+COBJS	+= cpu.o
+endif
+
 COBJS  += syslib.o
 
 SRCS	:= $(START:.o=.S) $(COBJS:.o=.c)