pinctrl: mediatek: Fix the invalid conditions

pinctrl: mediatek: Fix the invalid conditions

The variable count_reg_names is defined as an int type and cannot be
directly compared to an unsigned int. To resolve this issue,
first verify the correctness of count_reg_names.

Link: https://lore.kernel.org/all/5ae93d42e4c4e70fb33bf35dcc37caebf324c8d3.camel@mediatek.com/T/
Signed-off-by: Hao Chang <ot_chhao.chang@mediatek.com>
Signed-off-by: Qingliang Li <qingliang.li@mediatek.com>
Link: https://lore.kernel.org/20250329024533.5279-1-ot_chhao.chang@mediatek.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>