Revert "arm: add support for LZ4-compressed kernels"

This reverts commit 4a89ab15f2a8dec52b7f275c378c3e57a976581b.

Conflicts:
	arch/arm/boot/compressed/Makefile
Revert "lib: add support for LZ4-compressed kernels"

This reverts commit bce59ad4cec16b22c8a6e939aa572a4c24741d8c.

Conflicts:
	lib/lz4/lz4_decompress.c
Revert "decompressors: add lz4 decompressor module"

This reverts commit 97994c95aa46c01d80f705c730a757e251655650.