Convert CONFIG_SAMSUNG_ONENAND to Kconfig

This converts the following to Kconfig:
   CONFIG_SAMSUNG_ONENAND

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
diff --git a/configs/smdkc100_defconfig b/configs/smdkc100_defconfig
index 8c89c39..5f2ab44 100644
--- a/configs/smdkc100_defconfig
+++ b/configs/smdkc100_defconfig
@@ -36,6 +36,7 @@
 CONFIG_ENV_IS_IN_ONENAND=y
 # CONFIG_MMC is not set
 CONFIG_MTD=y
+CONFIG_SAMSUNG_ONENAND=y
 CONFIG_SMC911X=y
 CONFIG_SMC911X_BASE=0x98800300
 CONFIG_PWM_S5P=y