pinctrl: intel: Make use of struct pinfunction and PINCTRL_PINFUNCTION()

[ Upstream commit 999b85bf ]

Since pin control provides a generic data type and a macro for
the pin function definition, use them in the Intel driver.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Stable-dep-of: fed6d9a8 ("pinctrl: baytrail: Fix selecting gpio pinctrl state")
Signed-off-by: Sasha Levin <sashal@kernel.org>