configure: Fix GDB version detection for GDB_HAS_MTE

configure: Fix GDB version detection for GDB_HAS_MTE

The test gdbstub/test-mte.py requires a GDB version that supports the
qIsAddressTagged packet. According to GDB NEWS [0], this packet was
first made available in the GDB 15.1 release, not in 15.0, so this
commit fixes it in configure.

[0] https://www.sourceware.org/gdb/news/

Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2477
Message-Id: <20240804161850.2646299-4-gustavo.romero@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240813202329.1237572-6-alex.bennee@linaro.org>