package/pkgconf: bump to 1.5.3, change upstream

package/pkgconf: bump to 1.5.3, change upstream

The pkgconf project now has a website at pkgconf.org, and hosts its
tarballs at https://distfiles.dereferenced.org/pkgconf/, so this
commit updates the upstream location, and uses the xz-compressed
tarball as well.

pkgconf is bumped to 1.5.3. What prompted this update is the fact that
GStreamer uses the --define-prefix option when calling pkg-config, and
this option didn't exist in pkgconf 0.9.2.

The patch 0001-Fix-all-variables-sysroot-prefix-problem.patch is
dropped, because pkgconf now behaves properly, by prefixing all paths
with the sysroot. This has been verified by testing libdir and
includedir in zlib.pc, and adding some dummy pkgdatadir, mapdir and
sdkdir variables:

$ cat staging/usr/lib/pkgconfig/zlib.pc
prefix=/usr
exec_prefix=${prefix}
libdir=${exec_prefix}/lib
sharedlibdir=${libdir}
includedir=${prefix}/include
pkgdatadir=${prefix}/pouet
mapdir=${prefix}/this/is/map/dir
sdkdir=${prefix}/this/is/sdk/dir
[...]

$ ./host/bin/pkg-config --variable=libdir zlib
./host/bin/../arm-buildroot-linux-uclibcgnueabi/sysroot/usr/lib
$ ./host/bin/pkg-config --variable=includedir zlib
./host/bin/../arm-buildroot-linux-uclibcgnueabi/sysroot/usr/include
$ ./host/bin/pkg-config --variable=mapdir zlib
./host/bin/../arm-buildroot-linux-uclibcgnueabi/sysroot/usr/this/is/map/dir
$ ./host/bin/pkg-config --variable=sdkdir zlib
./host/bin/../arm-buildroot-linux-uclibcgnueabi/sysroot/usr/this/is/sdk/dir
$ ./host/bin/pkg-config --variable=pkgdatadir zlib
./host/bin/../arm-buildroot-linux-uclibcgnueabi/sysroot/usr/pouet

So, the 0001-Fix-all-variables-sysroot-prefix-problem patch is no
longer necessary.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Tested-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Acked-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>