Samsung defconfig changes for v5.5

1. Enable Dynamic Memory Controller driver for Exynos5422,
2. Enable Arndale (Exynos5250) audio driver,
3. Sync multi_v7 defconfig with exynos by enabling useful and necessary
   drivers (NFC, watchdog, S2MPA01 regulator, IOMMU, Maxim extcon
   drivers, PHY for SATA and devfreq).