Convert CONFIG_SYS_DDR_RAW_TIMING to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_DDR_RAW_TIMING

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/ls1043ardb_defconfig b/configs/ls1043ardb_defconfig
index 454f3dc..243a030 100644
--- a/configs/ls1043ardb_defconfig
+++ b/configs/ls1043ardb_defconfig
@@ -49,6 +49,7 @@
 CONFIG_FSL_CAAM=y
 # CONFIG_DDR_SPD is not set
 CONFIG_ECC_INIT_VIA_DDRCONTROLLER=y
+CONFIG_SYS_DDR_RAW_TIMING=y
 CONFIG_MPC8XXX_GPIO=y
 CONFIG_DM_I2C=y
 CONFIG_SPL_SYS_I2C_LEGACY=y