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/configs/sagem_f@st1704_ram_defconfig b/configs/sagem_f@st1704_ram_defconfig
index ab168a2..35ce6ae 100644
--- a/configs/sagem_f@st1704_ram_defconfig
+++ b/configs/sagem_f@st1704_ram_defconfig
@@ -1,4 +1,5 @@
 CONFIG_MIPS=y
+CONFIG_SKIP_LOWLEVEL_INIT=y
 CONFIG_SYS_TEXT_BASE=0x80010000
 CONFIG_NR_DRAM_BANKS=1
 CONFIG_ENV_SIZE=0x2000
@@ -6,6 +7,8 @@
 CONFIG_DEFAULT_DEVICE_TREE="sagem,f@st1704"
 CONFIG_ARCH_BMIPS=y
 CONFIG_SOC_BMIPS_BCM6338=y
+CONFIG_MIPS_CACHE_SETUP=y
+CONFIG_MIPS_CACHE_DISABLE=y
 # CONFIG_MIPS_BOOT_CMDLINE_LEGACY is not set
 # CONFIG_MIPS_BOOT_ENV_LEGACY is not set
 CONFIG_MIPS_BOOT_FDT=y