omap4/5/am33xx: Make lowlevel_init available to all armv7 platforms

Make the lowlevel_init function that these platforms have which just
sets up the stack and calls a C function available to all armv7
platforms.  As part of this we change some of the macros that are used
to be more clear.  Previously (except for am335x evm) we had been
setting CONFIG_SYS_INIT_SP_ADDR to a series of new defines that are
equivalent to simply referencing NON_SECURE_SRAM_END.  On am335x evm we
should have been doing this initially and do now.

Cc: Sricharan R <r.sricharan@ti.com>
Tested-by: Allen Martin <amartin@nvidia.com>
Signed-off-by: Tom Rini <trini@ti.com>
diff --git a/include/configs/omap5_evm.h b/include/configs/omap5_evm.h
index 0884280..4d6de16 100644
--- a/include/configs/omap5_evm.h
+++ b/include/configs/omap5_evm.h
@@ -228,10 +228,7 @@
 #define CONFIG_NR_DRAM_BANKS	1
 
 #define CONFIG_SYS_SDRAM_BASE		0x80000000
-#define CONFIG_SYS_INIT_RAM_ADDR	0x4030D800
-#define CONFIG_SYS_INIT_RAM_SIZE	0x800
-#define CONFIG_SYS_INIT_SP_ADDR		(CONFIG_SYS_INIT_RAM_ADDR + \
-					 CONFIG_SYS_INIT_RAM_SIZE - \
+#define CONFIG_SYS_INIT_SP_ADDR         (NON_SECURE_SRAM_END - \
 					 GENERATED_GBL_DATA_SIZE)
 
 #define CONFIG_SYS_EMIF_PRECALCULATED_TIMING_REGS
@@ -246,7 +243,7 @@
 #define CONFIG_SPL
 #define CONFIG_SPL_TEXT_BASE		0x40300350
 #define CONFIG_SPL_MAX_SIZE		0x19000	/* 100K */
-#define CONFIG_SPL_STACK		LOW_LEVEL_SRAM_STACK
+#define CONFIG_SPL_STACK		CONFIG_SYS_INIT_SP_ADDR
 
 #define CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR	0x300 /* address 0x60000 */
 #define CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS	0x200 /* 256 KB */