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/configs/a5y17lte_defconfig b/configs/a5y17lte_defconfig
index 4876a36..44915ea 100644
--- a/configs/a5y17lte_defconfig
+++ b/configs/a5y17lte_defconfig
@@ -10,6 +10,8 @@
 CONFIG_NR_DRAM_BANKS=12
 CONFIG_DEFAULT_DEVICE_TREE="exynos78x0-axy17lte"
 CONFIG_SYS_LOAD_ADDR=0x40001000
+CONFIG_HAS_CUSTOM_SYS_INIT_SP_ADDR=y
+CONFIG_CUSTOM_SYS_INIT_SP_ADDR=0x40200e50
 CONFIG_FIT=y
 CONFIG_USE_PREBOOT=y
 CONFIG_PREBOOT="echo Read pressed buttons status;KEY_VOLUMEUP=gpa20;KEY_HOME=gpa17;KEY_VOLUMEDOWN=gpa21;KEY_POWER=gpa00;PRESSED=0;RELEASED=1;if gpio input $KEY_VOLUMEUP; then setenv VOLUME_UP $PRESSED; else setenv VOLUME_UP $RELEASED; fi;if gpio input $KEY_VOLUMEDOWN; then setenv VOLUME_DOWN $PRESSED; else setenv VOLUME_DOWN $RELEASED; fi;if gpio input $KEY_HOME; then setenv HOME $PRESSED; else setenv HOME $RELEASED; fi;if gpio input $KEY_POWER; then setenv POWER $PRESSED; else setenv POWER $RELEASED; fi;"