[rbp] fixed compile on raspberrypi

fixing the following compile error on raspberrypi introduced by https://github.com/xbmc/xbmc/pull/2691

make: Entering directory `/media/usbdisk/xbmc/xbmc-bcm/xbmc-rbp/xbmc/windowing/egl'
CPP     xbmc/windowing/egl/EGLNativeTypeAmlogic.o
In file included from /media/usbdisk/xbmc/xbmc-bcm/buildroot-rbp/output/host/usr/arm-unknown-linux-gnueabi/sysroot/usr/include/linux/fb.h:5:0,
                 from EGLNativeTypeAmlogic.cpp:31:
                 /media/usbdisk/xbmc/xbmc-bcm/buildroot-rbp/output/host/usr/arm-unknown-linux-gnueabi/sysroot/usr/include/linux/i2c.h:126:7: error: multiple types in one declaration
                 /media/usbdisk/xbmc/xbmc-bcm/buildroot-rbp/output/host/usr/arm-unknown-linux-gnueabi/sysroot/usr/include/linux/i2c.h:126:7: error: declaration does not declare anything [-fpermissive]
                 make: *** [EGLNativeTypeAmlogic.o] Fehler 1