libsidplay2: fix build on ppc64le by not autoreconfiguring

libsidplay2: fix build on ppc64le by not autoreconfiguring

The libsidplay2 package build system is completely broken. It is made
of a top-level configure script, which calls into sub-configure
scripts in sub-directories. However, since it doesn't use the autoconf
provided AC_CONFIG_SUBDIRS() mechanism, an "autoreconf" doesn't
recurse into the subdirectories.

Due to this, the aclocal.m4 in the libsidplay/ subdirectory doesn't
get re-generated when Buildroot autoreconfs the package. However,
since we patch one of the .m4 files in this subdirectory, when build
time comes, the package notices its aclocal.m4 is older than one of
the .m4 file, and triggers an automatic autoreconf.

Since <pkg>_AUTORECONF = YES is enabled, this automatic autoreconf
works fine: host-autoconf and host-automake are available.

Expect that on powerpc64le, we patch the configure script itself to
make it recognize powerpc64le. But this patching of the configure
script itself gets overwritten by the automatic autoreconf at the
beginning of the build step, causing the build to fail on powerpc64le.

Switching to AC_CONFIG_SUBDIRS() would allow to fix this, but
libsidplay2 needs to pass custom configure options to each of the
sub-configure scripts, something that AC_CONFIG_SUBDIRS() doesn't
support. And since libsidplay2 upstream looks completely dead, the
incentive to fix the whole thing is very limited.

Since what's broken is the autoreconfiguration of the package, what we
do is modify patch 0001-sidplay2-libs-2.1.1.patch to directly tweak the
configure script (instead of the relevant .m4 file). Thanks to this,
<pkg>_AUTORECONF = YES is no longer needed, the .m4 file is no longer
newer than the sub-configure script, and no automatic autoreconf
triggers at build time. This allows the package to build properly on
powerpc64le.

While we normally don't like patching 'configure' scripts directly, in
this case the size of the change in the configure script is very small,
and as explained above, the incentive to fix the package properly is
very limited.

In detail, the changes:

 * Patch 0001-sidplay2-libs-2.1.1.patch is turned into a Git-formatted
   patch

 * The irrelevant changes to Makefile.in files, aclocal.m4, config.h.in,
   sidint.h are removed.

 * The change to my_macros.m4 is applied directly to the corresponding
   configure script.

 * The change to the configure.ac script regarding libdir is applied
   directly to the corresponding configure script.

 * The change to the configure.ac script regarding "*-k*bsd*-gnu" is
   dropped, since we don't care about kFreeBSD support.

 * LIBSIDPLAY2_AUTORECONF = YES is dropped from the .mk file.

Fixes:

  http://autobuild.buildroot.net/results/1f6a42bfece24e09c9c7f4078d549ec5c099c89d/

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