pinctrl: at91-pio4: add support for fewer lines on last PIO bank

pinctrl: at91-pio4: add support for fewer lines on last PIO bank

Some products, like sama7g5, do not have a full last bank of PIO lines.
In this case for example, sama7g5 only has 8 lines for the PE bank.
PA0-31, PB0-31, PC0-31, PD0-31, PE0-7, in total 136 lines.
To cope with this situation, added a data attribute that is product dependent,
to specify the number of lines of the last bank.
In case this number is different from the macro ATMEL_PIO_NPINS_PER_BANK,
adjust the total number of lines accordingly.
This will avoid advertising 160 lines instead of the actual 136, as this
product supports, and to avoid reading/writing to invalid register addresses.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20201113132429.420940-1-eugen.hristev@microchip.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>