gpio: regmap: fix kernel-doc notation

gpio: regmap: fix kernel-doc notation

Add a ':' to the end of struct member names to prevent kernel-doc
warnings:

Warning: include/linux/gpio/regmap.h:108 struct member 'regmap_irq_line'
 not described in 'gpio_regmap_config'
Warning: include/linux/gpio/regmap.h:108 struct member 'regmap_irq_flags'
 not described in 'gpio_regmap_config'

Fixes: 553b75d4bfe9 ("gpio: regmap: Allow to allocate regmap-irq device")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Michael Walle <mwalle@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20251128062739.845403-1-rdunlap@infradead.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>