pinctrl: fix incorrect inline keyword in multiple drivers

When building with 'make W=1', we get harmless warnings about
five drivers in drivers/pinctrl, which all contain a copy of
the same line:

drivers/pinctrl/freescale/pinctrl-imx1-core.c:160:1: error: 'inline' is not at beginning of declaration [-Werror=old-style-declaration]

This replaces the somewhat nonstandard 'static const inline'
with 'static inline const', which has the same meaning but
does not cause this warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>