pinctrl: pinconf-generic: fix an enum name description

pinctrl: pinconf-generic: fix an enum name description

Correct an enum name in a kernel-doc comment to avoid kernel-doc
warnings:

Warning: include/linux/pinctrl/pinconf-generic.h:161 Enum value
 'PIN_CONFIG_SKEW_DELAY_OUTPUT_PS' not described in enum 'pin_config_param'
Warning: include/linux/pinctrl/pinconf-generic.h:161 Excess enum value
 '@PIN_CONFIG_SKEW_DELAY_OUPUT_PS' description in 'pin_config_param'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Linus Walleij <linusw@kernel.org>