Fix a spelling/typo while we're here.

Fixes the following W=1 kernel build warning(s):

 drivers/pinctrl/pinconf-generic.c:242: warning: Function parameter or member 'pctldev' not described in 'pinconf_generic_parse_dt_config'
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200713144930.1034632-15-lee.jones@linaro.orgSigned-off-by: Linus Walleij <linus.walleij@linaro.org>