Samsung msm7x27: Use XZ compression to minimize kernel size

Change-Id: I936edc21fabb81733080346907b8f97a359117ed
(cherry picked from commit 8ab48679804efb0469fe9c00feb279de8d4acd74)
Conflicts:
	arch/arm/configs/cm7gen1_defconfig
	arch/arm/configs/cm7gen2_defconfig
	arch/arm/configs/cyanogen_blade_defconfig
	arch/arm/configs/msm7627-perf_defconfig
	arch/arm/configs/msm7627_blade2_p736v_defconfig
	arch/arm/configs/qsd8650-perf_defconfig