xen/arm: Set ThumbEE as not present in PFR0

Force ThumbEE support to not available in the version of the PFR0
register value we present to guest.
Xen does not support ThumbEE and will trap all access to ThumbEE
registers so do not report it being supported if the hardware supports
it.

Fixes: 5bbe1fe413 ("ARM: Drop ThumbEE support")
Signed-off-by: Bertrand Marquis <bertrand.marquis@arm.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Luca Fancellu <luca.fancellu@arm.com>
Tested-by: Luca Fancellu <luca.fancellu@arm.com>

xen/arch/arm/cpufeature.c

@@ -227,6 +227,9 @@ static int __init create_domain_cpuinfo(void)
 #endif
     domain_cpuinfo.pfr32.amu = 0;
 
+    /* Hide ThumbEE support */
+    domain_cpuinfo.pfr32.thumbee = 0;
+
     /* Hide RAS support as Xen does not support it */
 #ifdef CONFIG_ARM_64
     domain_cpuinfo.pfr64.ras = 0;