KVM: arm/arm64: Fix up includes for trace.h

Fedora kernel builds on armv7hl began failing recently because
kvm_arm_exception_type and kvm_arm_exception_class were undeclared in
trace.h. Add the missing include.

Fixes: 0e20f5e ("KVM: arm/arm64: Cleanup MMIO handling")
Signed-off-by: Jeremy Cline <jcline@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200205134146.82678-1-jcline@redhat.com

virt/kvm/arm/trace.h

@@ -4,6 +4,7 @@
 
 #include <kvm/arm_arch_timer.h>
 #include <linux/tracepoint.h>
+#include <asm/kvm_arm.h>
 
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM kvm