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/i2c/imx_i2c.c b/hw/i2c/imx_i2c.c
index e19d4fa..37e5a62 100644
--- a/hw/i2c/imx_i2c.c
+++ b/hw/i2c/imx_i2c.c
@@ -21,6 +21,7 @@
 #include "qemu/osdep.h"
 #include "hw/i2c/imx_i2c.h"
 #include "hw/i2c/i2c.h"
+#include "qemu/log.h"
 
 #ifndef DEBUG_IMX_I2C
 #define DEBUG_IMX_I2C 0