fix gcc4.7 compile

Signed-off-by: Dennis Rassmann <showp1984@gmail.com>

Conflicts:

	arch/arm/boot/compressed/Makefile

Conflicts:
	arch/arm/boot/compressed/Makefile

Change-Id: I1d8ce3a3147a2ded9de96f78f0f7f4b3db957b5f
Makefile: adding config variable for Os/O2/O3 compilation

Change-Id: I717acc7022048d2cb9920a348bbd78b7eff46bc5
Signed-off-by: Josue Rivera <prbassplayer@gmail.com>