ANDROID: irqchip: Kconfig: Make QCOM_PDC depend on QCOM_SCM || !QCOM_SCM

The qcom-pdc code calls qcom_scm_*, and since the QCOM_SCM
config can now be set as a module, this requires the QCOM_PDC
also be a module in that case, so make the dependency explicit
in the Kconfig.

This is done via the non-intuitive "depends on QCOM_SCM || !QCOM_SCM"
Kconfig syntax, which basically ensures that QCOM_SCM isn't
configured as a module if ARM_SMMU is built in.

Fixes: 6a1652ef ("ANDROID: firmware: QCOM_SCM: Allow qcom_scm driver to be loadable as a permenent module")
Signed-off-by: John Stultz <john.stultz@linaro.org>
Change-Id: Ie1a3c0644e49646c2b071b878cf1263d46be8e0d