ARM: defconfig: update Gemini defconfig

This updates the Gemini defconfig with drivers merged
for v4.13 or v4.14:
- ATA driver is merged
- DMA driver is merged
- RTC driver gets selected from default Kconfig

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>