plugins: fix win plugin tests on cross compile

plugins: fix win plugin tests on cross compile

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1972

Cross compile gcc is more picky about argument order than msys. Changed
the meson command to take the (now renamed) libqemu_plugin_api.a as a
lib, rather than an object. This puts it in the right place on both
native and cross compile gcc commands

Reenable plugins on crossbuilds

Signed-off-by: Greg Manning <gmanning@rapitasystems.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20231109124326.21106-2-gmanning@rapitasystems.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231120150833.2552739-5-alex.bennee@linaro.org>