arm64: defconfig: Enable CONFIG_ARM_SMMU_POWER_ON_ALWAYS for GKI targets

Enable CONFIG_ARM_SMMU_POWER_ON_ALWAYS for all GKI targets, and only
in the GKI configuration. This feature should not be enabled in
the QGKI/production configurations.

Change-Id: Ifa16169b2595408d4f5c2142f6fddb9aa941eb2a
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>