ARM: dts: dra7x-evm: Prevent glitch on DCAN1 pinmux

Driver core sets "default" pinmux on on probe and CAN driver
sets "sleep" pinmux during register. This causes a small window
where the CAN pins are in "default" state with the DCAN module
being disabled.

Change the "default" state to be like sleep so this glitch is
avoided. Add a new "active" state that is used by the driver
when CAN is actually active.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>