arm64: hyperv: Initialize the Virtual Trust Level field

Various parts of the hyperv code need to know what VTL
the kernel runs at, most notably VMBus needs that to
establish communication with the host.

Initialize the Virtual Trust Level field to enable
booting in the Virtual Trust Level.

Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/20250428210742.435282-6-romank@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250428210742.435282-6-romank@linux.microsoft.com>

Author: romank-msft

arch/arm64/hyperv/mshyperv.c

@@ -117,6 +117,7 @@ static int __init hyperv_init(void)
 
 	if (ms_hyperv.priv_high & HV_ACCESS_PARTITION_ID)
 		hv_get_partition_id();
+	ms_hyperv.vtl = get_vtl();
 
 	ms_hyperv_late_init();