hw: move private headers to hw/ subdirectories.

Many headers are used only in a single directory.  These can be
kept in hw/.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/hw/intc/arm_gic_kvm.c b/hw/intc/arm_gic_kvm.c
index 22b40b4..b756456 100644
--- a/hw/intc/arm_gic_kvm.c
+++ b/hw/intc/arm_gic_kvm.c
@@ -21,7 +21,7 @@
 #include "hw/sysbus.h"
 #include "sysemu/kvm.h"
 #include "kvm_arm.h"
-#include "hw/arm_gic_internal.h"
+#include "gic_internal.h"
 
 #define TYPE_KVM_ARM_GIC "kvm-arm-gic"
 #define KVM_ARM_GIC(obj) \