pinctrl: pinconf-generic: Add properties 'input-threshold-voltage-microvolt'

pinctrl: pinconf-generic: Add properties 'input-threshold-voltage-microvolt'

Add a new generic pin configuration parameter PIN_CONFIG_INPUT_VOLTAGE_UV.
This parameter is used to specify the input voltage level of a pin in
microvolts, which corresponds to the 'input-voltage-microvolt' property
in Device Tree.

Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Tzuyi Chang <tychang@realtek.com>
Co-developed-by: Yu-Chun Lin <eleanor.lin@realtek.com>
Signed-off-by: Yu-Chun Lin <eleanor.lin@realtek.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>