Remove include <log.h> from defines.h

The reason for this is that log.h includes drv_hrt.h which sucks in
half the project's include files with it, which causes strange build
issues

src/drivers/uavcan/sensors/battery.cpp

@@ -35,6 +35,7 @@
 
 #include <lib/geo/geo.h>
 #include <px4_defines.h>
+#include <px4_platform_common/log.h>
 
 const char *const UavcanBatteryBridge::NAME = "battery";