ARM: keystone: Enable PINCTRL config

Some Keystone 2 devices utilize pinmuxing which requires PINCTRL
to be enabled. Therefore, enable PINCTRL for all Keystone 2 devices.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>