gdb: add PACKAGECONFIG for xz (lzma) compression support

Similar to elfutils, when xz support is built into gdb it will be able
to read xz-compressed ELF sections containing debuginfo. This is used by
the "mini debuginfo" format:
https://sourceware.org/gdb/onlinedocs/gdb/MiniDebugInfo.html

(From OE-Core rev: b7e2f53745977f3f4a472f352e318b4bea8b20f9)

Signed-off-by: Dan Callaghan <dan.callaghan@opengear.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/gdb/gdb-common.inc

@@ -19,7 +19,7 @@ EXPAT = "--with-expat --with-libexpat-prefix=${STAGING_DIR_HOST}"
 
 EXTRA_OECONF = "--disable-gdbtk --disable-x --disable-werror \
                 --with-curses --disable-multilib --disable-sim \
-                --without-lzma --without-guile \
+                --without-guile \
                 ${GDBPROPREFIX} ${EXPAT} \
                 ${@bb.utils.contains('DISTRO_FEATURES', 'multiarch', '--enable-64-bit-bfd', '', d)} \
                 --disable-rpath \
@@ -35,6 +35,7 @@ PACKAGECONFIG[python] = "--with-python=${WORKDIR}/python,--without-python,python
 PACKAGECONFIG[babeltrace] = "--with-babeltrace,--without-babeltrace,babeltrace"
 # ncurses is already a hard DEPENDS, but would be added here if it weren't
 PACKAGECONFIG[tui] = "--enable-tui,--disable-tui"
+PACKAGECONFIG[xz] = "--with-lzma,--without-lzma,xz"
 
 GDBPROPREFIX = "--program-prefix=''"