arm64: enable more compressed Image formats

Plumb up Makefile arguments for the already supported formats in the kbuild
system: lz4, bzip2, lzma, and lzo.

Note that just as with Image.gz, these images are not self-decompressing and
the booting firmware still needs to handle decompression before launching the
kernel image.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 4d2a925..0953a97 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -58,7 +58,10 @@
 
 boot := arch/arm64/boot
 
-Image Image.gz: vmlinux
+Image: vmlinux
+	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
+
+Image.%: vmlinux
 	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
 
 zinstall install: vmlinux