Makefile: allow 'make uninstall'

Makefile: allow 'make uninstall'

Meson supports an "uninstall", so we can easily allow it to work by
not suppressing the forwarding of it from Make to meson.

We originally suppressed this because Meson's 'uninstall' has a hole
in it: it will remove everything that is installed by a mechanism
meson knows about, but not things installed by "custom install
scripts", and there is no "custom uninstall script" mechanism.

For QEMU, though, the only thing that was being installed by a custom
install script was the LC_MESSAGES files handled by Meson's i18n
module, and that code was fixed in Meson commit 487d45c1e5bfff0fbdb4,
which is present in Meson 0.60.0 and later.  Since we already require
a Meson version newer than that, we're now safe to enable
'uninstall', as it will now correctly uninstall everything that was
installed.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/109
Message-Id: <20230110151250.24434-1-peter.maydell@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>