gpio: bcm-kona: fix bcm_kona_gpio_reset() warnings

The bcm_kona_gpio_reset() calls bcm_kona_gpio_write_lock_regs()
with what looks like the wrong parameter. The write_lock_regs
function takes a pointer to the registers, not the bcm_kona_gpio
structure.

Fix the warning, and probably bug by changing the function to
pass reg_base instead of kona_gpio, fixing the following warning:

drivers/gpio/gpio-bcm-kona.c:550:47: warning: incorrect type in argument 1
  (different address spaces)
  expected void [noderef] <asn:2>*reg_base
  got struct bcm_kona_gpio *kona_gpio
  warning: incorrect type in argument 1 (different address spaces)
  expected void [noderef] <asn:2>*reg_base
  got struct bcm_kona_gpio *kona_gpio

Cc: stable@vger.kernel.org
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Acked-by: Ray Jui <ray.jui@broadcom.com>
Reviewed-by: Markus Mayer <mmayer@broadcom.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>