pinctrl: samsung: pinctrl-s3c64xx: Fix formatting issues

pinctrl: samsung: pinctrl-s3c64xx: Fix formatting issues

Kerneldoc struct titles must be followed by whitespace else the
checker gets confused.

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

 drivers/pinctrl/samsung/pinctrl-s3c64xx.c:212: warning: cannot understand function prototype: 'struct s3c64xx_eint0_domain_data '

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Cc: Tomasz Figa <tomasz.figa@gmail.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: linux-samsung-soc@vger.kernel.org
Link: https://lore.kernel.org/r/20200713144930.1034632-9-lee.jones@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>