MIPS: PMC MSP71XX gpio drivers

This new gpio driver for PMC-Sierra's MSP71xx SoC allows
standard api calls for access to the general and extended
gpio's.

Signed-off-by: Patrick Glass <patrickglass@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

 create mode 100755 arch/mips/pmc-sierra/msp71xx/gpio.c
 create mode 100755 arch/mips/pmc-sierra/msp71xx/gpio_extended.c
 create mode 100755 include/asm-mips/pmc-sierra/msp71xx/gpio.h