pinconf-generic: clarify pull up and pull down config values

PIN_CONFIG_BIAS_PULL_DOWN and PIN_CONFIG_BIAS_PULL_UP values can
be custom or an SI unit such as ohms
Signed-off-by: Niyas Sait <niyas.sait@linaro.org>
Link: https://lore.kernel.org/r/20221115175415.650690-3-niyas.sait@linaro.orgSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

include/linux/pinctrl/pinconf-generic.h

@@ -38,7 +38,8 @@ struct pinctrl_map;
  *	impedance.
  * @PIN_CONFIG_BIAS_PULL_DOWN: the pin will be pulled down (usually with high
  *	impedance to GROUND). If the argument is != 0 pull-down is enabled,
- *	if it is 0, pull-down is total, i.e. the pin is connected to GROUND.
+ *	the value is interpreted by the driver and can be custom or an SI unit
+ *  such as ohms.
  * @PIN_CONFIG_BIAS_PULL_PIN_DEFAULT: the pin will be pulled up or down based
  *	on embedded knowledge of the controller hardware, like current mux
  *	function. The pull direction and possibly strength too will normally
@@ -49,7 +50,8 @@ struct pinctrl_map;
  *	@PIN_CONFIG_BIAS_DISABLE.
  * @PIN_CONFIG_BIAS_PULL_UP: the pin will be pulled up (usually with high
  *	impedance to VDD). If the argument is != 0 pull-up is enabled,
- *	if it is 0, pull-up is total, i.e. the pin is connected to VDD.
+ *	the value is interpreted by the driver and can be custom or an SI unit
+ *  such as ohms.
  * @PIN_CONFIG_DRIVE_OPEN_DRAIN: the pin will be driven with open drain (open
  *	collector) which means it is usually wired with other output ports
  *	which are then pulled up with an external resistor. Setting this