[MIPS] txx9: convert gpio driver to use gpio_chip_ops

The GPIO controller operations has been split to be stored
on a separate struct gpio_chip_ops virtual function table

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
MIPS: Loongson 2F: convert gpio driver to use gpio_chip_ops

The GPIO controller operations has been split to be stored
on a separate struct gpio_chip_ops virtual function table

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
MIPS: RB532: convert gpio driver to use gpio_chip_ops

The GPIO controller operations has been split to be stored
on a separate struct gpio_chip_ops virtual function table

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
MIPS: TXx9: convert gpio driver to use gpio_chip_ops

The GPIO controller operations has been split to be stored
on a separate struct gpio_chip_ops virtual function table

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
MIPS: TXx9: convert rbtx4938 gpio driver to use gpio_chip_ops

The GPIO controller operations has been split to be stored
on a separate struct gpio_chip_ops virtual function table

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>