Add IMX_SC_R_CAN(x) macro for CAN.

Suggested-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Link: https://lore.kernel.org/r/20201106105627.31061-5-qiangqing.zhang@nxp.com


Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>