arm64: kvm, smccc: Fix vendor uuid

Commit 1342306 ("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: 1342306 ("arm64: kvm, smccc: Introduce and use API for getting hypervisor UUID")
Signed-off-by: Jack Thomson <[email protected]>
Reviewed-by: Marc Zyngier <[email protected]>
Tested-by: Marc Zyngier <[email protected]>
Reviewed-by: Sudeep Holla <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>

Author: JackThomson2

include/linux/arm-smccc.h

@@ -113,7 +113,7 @@
 
 /* KVM UID value: 28b46fb6-2ec5-11e9-a9ca-4b564d003a74 */
 #define ARM_SMCCC_VENDOR_HYP_UID_KVM UUID_INIT(\
-	0xb66fb428, 0xc52e, 0xe911, \
+	0x28b46fb6, 0x2ec5, 0x11e9, \
 	0xa9, 0xca, 0x4b, 0x56, \
 	0x4d, 0x00, 0x3a, 0x74)