ARM64: hisi fixes for 4.18

- Added power capabilities for the mmc host controller on the
  hikey and hikey960 boards to avoid broken wifi.

* tag 'hisi-fixes-for-4.18' of git://github.com/hisilicon/linux-hisi

:
  arm64: dts: hikey960: Define wl1837 power capabilities
  arm64: dts: hikey: Define wl1835 power capabilities

Signed-off-by: Olof Johansson <olof@lixom.net>