MIPS: ip22-gio: Make gio_match_device() static

Unlike its PCI counterpart, gio_match_device() was never used outside
the GIO bus code.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org