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/P1010RDB-PB_NAND_defconfig b/configs/P1010RDB-PB_NAND_defconfig
index b5d0017..726de84 100644
--- a/configs/P1010RDB-PB_NAND_defconfig
+++ b/configs/P1010RDB-PB_NAND_defconfig
@@ -82,6 +82,7 @@
 CONFIG_DDR_CLK_FREQ=66666666
 CONFIG_SYS_SPD_BUS_NUM=1
 CONFIG_CHIP_SELECTS_PER_CTRL=1
+CONFIG_SYS_DDR_RAW_TIMING=y
 CONFIG_TPL_COMMON_INIT_DDR=y
 CONFIG_DM_I2C=y
 CONFIG_SPL_SYS_I2C_LEGACY=y