pinctrl: single: Fix error return code in pcs_parse_bits_in_pinctrl_entry()

pinctrl: single: Fix error return code in pcs_parse_bits_in_pinctrl_entry()

Fix to return -ENOTSUPP instead of 0 when PCS_HAS_PINCONF is true, which
is the same as that returned in pcs_parse_pinconf().

Fixes: 4e7e8017a80e ("pinctrl: pinctrl-single: enhance to configure multiple pins of different modules")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Link: https://lore.kernel.org/r/20210722033930.4034-2-thunder.leizhen@huawei.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>