Revert "Add option to flag 4.8 builds for devices that do not support 4.9 yet"

This reverts commit 8564f75e33a87038c8c356d2c8fbc8dc5d2c2897.
Revert "Allow building with SaberMod/Linaro Toolchains"

This reverts commit 71a92a60a0d0bf6703ad6dae64cbeeb279c47c44.
Revert " 4.8 GCC, Strict Aliasing=3, -O3 CFLAG, Opt Flags!!"

This reverts commit 6c9e1ece1890b4848092b743b873f65d29cf7061.

Conflicts:
	core/combo/TARGET_linux-arm.mk
Revert "kernel: allow to specify a custom toolchain for kernel build"

This reverts commit e50220ea86f1b402ee6c69a54edcaf04d74a978f.
Revert "kernel.mk: workaround to fix kernel builds on darwin until the prebuilts/gcc is checked in by upstream."

This reverts commit cd1918ba86730a0bcdb1371ece88048bc195459b.