Convert CONFIG_SKIP_LOWLEVEL_INIT et al to Kconfig

This converts the following to Kconfig:
   CONFIG_SKIP_LOWLEVEL_INIT
   CONFIG_SKIP_LOWLEVEL_INIT_ONLY

In order to do this, we need to introduce SPL and TPL variants of these
options so that we can clearly disable these options only in SPL in some
cases, and both instances in other cases.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/cpu/armv8/fsl-layerscape/Kconfig b/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
index 9ca61b3..b10b56d 100644
--- a/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
+++ b/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
@@ -5,6 +5,7 @@
 	select FSL_LAYERSCAPE
 	select FSL_LSCH2
 	select GICV2
+	select SKIP_LOWLEVEL_INIT
 	select SYS_FSL_SRDS_1
 	select SYS_HAS_SERDES
 	select SYS_FSL_DDR_BE
@@ -62,6 +63,7 @@
 	select FSL_LSCH2
 	select GICV2
 	select HAS_FSL_XHCI_USB if USB_HOST
+	select SKIP_LOWLEVEL_INIT
 	select SYS_FSL_SRDS_1
 	select SYS_HAS_SERDES
 	select SYS_FSL_DDR
@@ -96,6 +98,7 @@
 	select FSL_LSCH2
 	select GICV2
 	select HAS_FSL_XHCI_USB if USB_HOST
+	select SKIP_LOWLEVEL_INIT
 	select SYS_FSL_SRDS_1
 	select SYS_HAS_SERDES
 	select SYS_FSL_DDR
@@ -134,6 +137,7 @@
 	select FSL_LAYERSCAPE
 	select FSL_LSCH3
 	select GICV3
+	select SKIP_LOWLEVEL_INIT
 	select SYS_FSL_SRDS_1
 	select SYS_HAS_SERDES
 	select SYS_FSL_DDR
@@ -181,6 +185,7 @@
 	select FSL_LAYERSCAPE
 	select FSL_LSCH3
 	select GICV3
+	select SKIP_LOWLEVEL_INIT
 	select SYS_FSL_SRDS_1
 	select SYS_HAS_SERDES
 	select SYS_FSL_DDR
@@ -296,6 +301,7 @@
 
 config FSL_LSCH2
 	bool
+	select SKIP_LOWLEVEL_INIT
 	select SYS_FSL_HAS_CCI400
 	select SYS_FSL_HAS_SEC
 	select SYS_FSL_SEC_COMPAT_5