ARM: mach-qcom: Add support for MSM8909

Add a Kconfig entry for MSM8909 and the "qcom,msm8909-smp" CPU
enable-method. The ARM Cortex-A7 cores are booted just like on MSM8226.

Signed-off-by: Stephan Gerhold <stephan.gerhold@kernkonzept.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220705143523.3390944-9-stephan.gerhold@kernkonzept.com