m25p80: Remove bogus include of devices.h

I think in the early revisions of this we had an instantiation helper
for the device in devices.h. This was later removed and this header was
left over. Removed

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

hw/block/m25p80.c

@@ -24,7 +24,6 @@
 #include "hw/hw.h"
 #include "sysemu/blockdev.h"
 #include "hw/ssi.h"
-#include "hw/devices.h"
 
 #ifndef M25P80_ERR_DEBUG
 #define M25P80_ERR_DEBUG 0