Remove .xzkern to be pushed

Signed-off-by: Amperific <amperific@gmail.com>
Revert "ASKP: Prep for GCC 4.8 with the inclusion of -O3 flags"

This reverts commit 9c71295b128a64df7cd4cddbbae28764c2cd70a8.

Signed-off-by: Amperific <amperific@gmail.com>

Conflicts:
	arch/arm/boot/compressed/piggy.xzkern