build: recovery: Support target specific resource selection

 * Allow resources matching the target screen width to override the
   default resources.
 * Allow overriding screen width for recovery.

Change-Id: I979b6e74cfd1fe66c798de02bcd908d22731494a
core: arm: Add support for GCC 4.8 and 4.9

Change-Id: I96bffffb4b0e16ef5bcedc85dedc70ca3dc2182f
core: arm: Use -O3 optimization inside TARGET_arm_CFLAGS

Change-Id: I224b62b3dada874d00a90258a1dcffcea09bc029