Implements OF support and convert to of_mm_gpio.

By attaching hardware latches to the External Bus Unit (EBU) on Lantiq SoC, it
is possible to create output only gpios. This driver configures a special
memory address, which when written to, outputs 16 bit to the latches.
Signed-off-by: NJohn Crispin <blogic@openwrt.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Patchwork: https://patchwork.linux-mips.org/patch/3840/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Move the 2 drivers from arch/mips/lantiq/xway/ to the subsystem and make them
buildable.

The following 2 patches will convert the drivers to OF.
Signed-off-by: NJohn Crispin <blogic@openwrt.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Patchwork: https://patchwork.linux-mips.org/patch/3838/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Correct spelling "platfom" to "platform", "deactived" to "deactivated"
and "deprectated" to "deprecated" in arch/mips directory.
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

The code located at arch/mips/lantiq/ included module.h to be able to use
the EXPORT_SYMBOL* macros. These can now be directly included using
export.h.
Signed-off-by: NJohn Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2937/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The XWAY family allows to extend the number of gpios by using shift
registers or latches. This patch adds the 2 drivers needed for this. The
extended gpios are output only.

[ralf@linux-mips.org: Fixed ltq_stp_probe section() attributes.]
Signed-off-by: NJohn Crispin <blogic@openwrt.org>
Signed-off-by: NRalph Hempel <ralph.hempel@lantiq.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2258/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>