Convert CONFIG_SPL_NAND_RAW_ONLY et al to Kconfig

This converts the following to Kconfig:
   CONFIG_SPL_NAND_RAW_ONLY
   CONFIG_SPL_NAND_SOFTECC

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/taurus_defconfig b/configs/taurus_defconfig
index 90f9133..8bc5afd 100644
--- a/configs/taurus_defconfig
+++ b/configs/taurus_defconfig
@@ -43,8 +43,10 @@
 CONFIG_SPL_SYS_MALLOC_SIMPLE=y
 CONFIG_SPL_CRC32=y
 CONFIG_SPL_NAND_SUPPORT=y
+CONFIG_SPL_NAND_RAW_ONLY=y
 CONFIG_SPL_NAND_DRIVERS=y
 CONFIG_SPL_NAND_ECC=y
+CONFIG_SPL_NAND_SOFTECC=y
 CONFIG_SPL_NAND_BASE=y
 CONFIG_SPL_DM_SPI_FLASH=y
 CONFIG_HUSH_PARSER=y