Convert CONFIG_MTD_PARTITIONS et al to Kconfig

This converts the following to Kconfig:
   CONFIG_MTD_PARTITIONS
   CONFIG_MTD_DEVICE

Signed-off-by: Adam Ford <aford173@gmail.com>
diff --git a/configs/T1042RDB_PI_SPIFLASH_defconfig b/configs/T1042RDB_PI_SPIFLASH_defconfig
index 8ba4dc1..c020273 100644
--- a/configs/T1042RDB_PI_SPIFLASH_defconfig
+++ b/configs/T1042RDB_PI_SPIFLASH_defconfig
@@ -46,6 +46,7 @@
 CONFIG_SYS_FSL_DDR3=y
 CONFIG_FSL_ESDHC=y
 CONFIG_MTD_NOR_FLASH=y
+CONFIG_MTD_PARTITIONS=y
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_STMICRO=y
 CONFIG_PHYLIB=y