irqchip/gic-v3: Add quirk for msm8996 broken registers

irqchip/gic-v3: Add quirk for msm8996 broken registers

Access to GICR_WAKER is restricted on msm8996 SoC in Hypervisor.
Its been more than 2+ years of wait for this to be fixed, which has
no hopes to be fixed. This change was introduced for the "lead device"
on msm8996 platform. It looks like all publicly available msm8996 and
other Qualcomm SoCs have this implementation.

So add a quirk to not access this register on msm8996.

With this quirk MSM8996 can at least boot out of mainline,
which can help community to work with boards based on MSM8996 and other
SoCs with have this restrictions. This Quirk is based on device tree
compatible string.

Without this patch Qualcomm DB820c board reboots when GICR_WAKER
is accessed.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>