i2c: st: add include for pinctrl

The driver uses pinctrl directly and thus should include the appropriate
header. Sort the headers while we are here to have a better view what is
included and what is not.

Reported-by: Pascal Huerst <pascal.huerst@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
1 file changed