arm64: defconfig: Enable HFPLL

arm64: defconfig: Enable HFPLL

The high frequency pll is required on compatible Qualcomm SoCs to
support the CPU frequency scaling feature.

Co-developed-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20191125142511.681149-6-niklas.cassel@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>