pinctrl/amd: Update contact information for AMD pinctrl/amd

Updating the point of contact for AMD GPIO driver.

Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Signed-off-by: Nehal Shah <Nehal-bakulchandra.Shah@amd.com>
Cc: Ken Xue <Ken.Xue@amd.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>