arm64: defconfig: enable i.MX91 pinctrl

Enable i.MX91 pinctrl driver for booting the system.

Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Pengfei Li <pengfei.li_1@nxp.com>
Signed-off-by: Joy Zou <joy.zou@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>