package/gdb: bump to version 9.2

package/gdb: bump to version 9.2

The in-tree build restriction has been added after the move of gnulib
to top level [1] [2].  This restriction has been added as a workaround
a build issue with gdbserver that still uses its own copy of gnulib.

gnulib is configured a second time if we build in-tree gdb and gdbserver:

    configure: error: source directory already configured; run "make distclean" there first
    configure: error: .././../../gnulib/configure failed for build-gnulib-gdbserver
    configure: error: ./configure failed for gdbserver

Use the same pre-configure-hook as gcc package.

Older gdb version support building out of tree even if it's not
required.

There is no in-tree build restriction of we only build gdbserver for
the target.

[1] https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=73cc72729a184f00bf6fc4d74684a8516ba6b683
[2] https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=043a0010933a6b55081535ecaf7fde9cc1491be0

See:
https://sourceware.org/pipermail/gdb-announce/2020/000122.html
https://sourceware.org/pipermail/gdb-announce/2020/000123.html

Signed-off-by: Maxim Kochetkov <fido_max@inbox.ru>
[Romain:
    - add in-tree build support
    - improve commit log]
Signed-off-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>