arm64: defconfig: Enable CPU clock drivers for Qualcomm msm8916

QCOM_A53PLL and QCOM_CLK_APCS_MSM8916 used to be enabled by default in
drivers/clk/qcom/Kconfig. A recent patch changed that by dropping the
'default ARCH_QCOM' directive.

Add the two options explicitly in the arm64 defconfig, to avoid
functional regressions.

Acked-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Marc Gonzalez <marc.w.gonzalez@free.fr>
[bjorn: Rewrote subject]
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>