hw: explicitly include qemu/log.h

Move the inclusion out of hw/hw.h, most files do not need it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/hw/misc/imx6_ccm.c b/hw/misc/imx6_ccm.c
index 4e1d49d..ec58eef 100644
--- a/hw/misc/imx6_ccm.c
+++ b/hw/misc/imx6_ccm.c
@@ -12,6 +12,7 @@
 
 #include "qemu/osdep.h"
 #include "hw/misc/imx6_ccm.h"
+#include "qemu/log.h"
 
 #ifndef DEBUG_IMX6_CCM
 #define DEBUG_IMX6_CCM 0