pinctrl: palmas: remove pin config BIAS_PULL_PIN_DEFAULT support

Palmas devices do not support the default bias configuration
and hence removing this option from valid pin config parameters.

Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>