This fixes build errors with external toolchains that don't
automatically search for headers in STAGING_DIR:

mipsel-linux-gnu-gcc   -I. -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE
-D_GNU_SOURCE -DCOMP_DEFAULT=\"gzip\" -Wall -DGZIP_SUPPORT   -c -o
gzip_wrapper.o gzip_wrapper.c
gzip_wrapper.c:27:18: fatal error: zlib.h: No such file or directory
 #include <zlib.h>
                  ^
compilation terminated.
make[3]: *** [gzip_wrapper.o] Error 1

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

Part of a wider housekeeping effort on the packages repository.

Signed-off-by: Alberto Bursi <alberto.bursi@outlook.it>

Otherwise it will pull all compression libraries to install
(on newly configured targets) when maybe 1 or 2 are needed.

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

Seems that this issue with squashfs-tools was fixed by the guys
at openembedded.
See patch here:
https://github.com/openembedded/openembedded-core/blob/master/meta/recipes-devtools/squashfs-tools/squashfs-tools/0001-mksquashfs.c-get-inline-functions-work-with-C99.patch

I think in my case, this issue appeared because I wrote the Makefile
some time ago and it worked, then when I did the PR for it,
it wasn't working anymore, and I assumed it was still working.

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

Picked up the old Makefile at 4.2.
Upgraded at 4.3 (repo move to github now: https://github.com/plougher/squashfs-tools/)
Added musl compatibility.
Enabled LZ4 compression support by default

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>