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/mx35pdk_defconfig b/configs/mx35pdk_defconfig
index 468b540..4178aa7 100644
--- a/configs/mx35pdk_defconfig
+++ b/configs/mx35pdk_defconfig
@@ -27,6 +27,7 @@
 CONFIG_MXC_GPIO=y
 CONFIG_FSL_ESDHC=y
 CONFIG_MTD_NOR_FLASH=y
+CONFIG_MTD_PARTITIONS=y
 CONFIG_NAND=y
 CONFIG_NAND_MXC=y
 CONFIG_NETDEVICES=y