Migrate CUSTOM_SYS_INIT_SP_ADDR to Kconfig using system-constants.h

- Make all users of CUSTOM_SYS_INIT_SP_ADDR reference SYS_INIT_SP_ADDR
- Introduce HAS_CUSTOM_SYS_INIT_SP_ADDR to allow for setting the stack
  pointer directly, otherwise we use the common calculation.
- On some platforms that were using the standard calculation but did not
  set CONFIG_SYS_INIT_RAM_SIZE / CONFIG_SYS_INIT_RAM_ADDR, set them.
- On a small number of platforms that were not subtracting
  GENERATED_GBL_DATA_SIZE do so now via the standard calculation.
- CONFIG_SYS_INIT_SP_OFFSET is now widely unused, so remove it from most
  board config header files.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/mips/mach-mtmips/mt7628/lowlevel_init.S b/arch/mips/mach-mtmips/mt7628/lowlevel_init.S
index 83cd8fa..cb369fb 100644
--- a/arch/mips/mach-mtmips/mt7628/lowlevel_init.S
+++ b/arch/mips/mach-mtmips/mt7628/lowlevel_init.S
@@ -12,16 +12,11 @@
 #include <asm/mipsregs.h>
 #include <asm/addrspace.h>
 #include <asm/asm.h>
+#include <system-constants.h>
 #include "mt7628.h"
 
-/* Set temporary stack address range */
-#ifndef CONFIG_SYS_INIT_SP_ADDR
-#define CONFIG_SYS_INIT_SP_ADDR	(CONFIG_SYS_SDRAM_BASE + \
-				CONFIG_SYS_INIT_SP_OFFSET)
-#endif
-
 #define CACHE_STACK_SIZE	0x4000
-#define CACHE_STACK_BASE	(CONFIG_SYS_INIT_SP_ADDR - CACHE_STACK_SIZE)
+#define CACHE_STACK_BASE	(SYS_INIT_SP_ADDR - CACHE_STACK_SIZE)
 
 #define DELAY_USEC(us)		((58 * (us)) / 3)
 
@@ -134,7 +129,7 @@
 
 #if CONFIG_IS_ENABLED(INIT_STACK_WITHOUT_MALLOC_F)
 	/* Set malloc base */
-	li	t0, (CONFIG_SYS_INIT_SP_ADDR + 15) & (~15)
+	li	t0, (SYS_INIT_SP_ADDR + 15) & (~15)
 	PTR_S	t0, GD_MALLOC_BASE(k0)	# gd->malloc_base offset
 #endif