arm64: dts: qcom: sc7180: Add EL2 overlay for WoA devices

arm64: dts: qcom: sc7180: Add EL2 overlay for WoA devices

WoA devices using sc7180 use android firmware to boot, which notably
includes QHEE hypervisor. This means that, so far, Linux-based OS could
only boot in EL1 on those devices.

However Windows can replace QHEE upon boot with it's own hypervisor, and
with the use of tools such as "slbounce", it's possible to do the same
for Linux-based OS, in which case some modifications to the DT are
necessary to facilitate the absence of QHEE services.

Add a EL2-specific DT overlay and apply it to sc7180 WoA devices to
create -el2.dtb for each of them alongside "normal" dtb.

Signed-off-by: Nikita Travkin <nikita@trvn.ru>
Link: https://lore.kernel.org/r/20250503-sc-el2-overlays-v2-1-24e9b4572e15@trvn.ru
Signed-off-by: Bjorn Andersson <andersson@kernel.org>