arm64: kvm, smccc: Fix vendor uuid

Commit 13423063 ("arm64: kvm, smccc: Introduce and use API for
getting hypervisor UUID") replaced the explicit register constants
with the UUID_INIT macro. However, there is an endian issue, meaning
the UUID generated and used in the handshake didn't match UUID prior to
the commit.

The change in UUID causes the SMCCC vendor handshake to fail with older
guest kernels, meaning devices such as PTP were not available in the
guest.

This patch updates the parameters to the macro to generate a UUID which
matches the previous value, and re-establish backwards compatibility
with older guest kernels.

Fixes: 13423063 ("arm64: kvm, smccc: Introduce and use API for getting hypervisor UUID")
Signed-off-by: Jack Thomson <jackabt@amazon.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20250721130558.50823-1-jackabt.amazon@gmail.com


Signed-off-by: Will Deacon <will@kernel.org>