ARM: ux500: bump arch nr of GPIOs

Set the number of GPIOs for Ux500 to 392. Reasoning:

- Internal pinctrl "Nomadik" SoC: 288 GPIOs
- Then each Ux500 system has one or two GPIO expanders at
  maximum 24 GPIOs each:
  TC35892 expander: 24 GPIOs
  STMPE1601 or 1801 Expander: 24 GPIOs
- Then AB8500/AB8505/AB8540: 56 GPIOs

Sum: maximum 392 GPIOs - no more no less.

Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>