pinctrl: aspeed: Use the right pinconf mask

The Aspeed pinconf data structures are split into 'conf' and 'map'
types, where the 'conf' struct defines which register and bitfield to
manipulate, while the 'map' struct defines what value to write to
the register and bitfield.

Both structs have a mask member, and the wrong mask was being used to
tell the regmap which bits to update.

A todo is to look at whether we can remove the mask from the 'map'
struct.

Fixes: 5f52c853 ("pinctrl: aspeed: Use masks to describe pinconf bitfields")
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Cc: Johnny Huang <johnny_huang@aspeedtech.com>
Link: https://lore.kernel.org/r/20200910025631.2996342-3-andrew@aj.id.au


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>