MIPS: GIO bus support for SGI IP22/28

SGI IP22/IP28 machines have GIO busses for adding graphics and other
extension cards. This patch adds support for GIO driver/device
handling and converts the newport console driver to a GIO driver.

[ralf@linux-mips.org: Fixed build error caused by the modules.h -> export.h
changes.]

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
To: linux-fbdev@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/2886/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>