remoteproc: imx_rproc: Add IMX_RPROC_SCU_API method

On i.MX8QM and i.MX8QXP, most devices are controlled
by System Control Unit, so add IMX_RPROC_SCU_API
method for these platform.

Signed-off-by: Shengjiu Wang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mathieu Poirier <[email protected]>

Author: TE-N-ShengjiuWang

drivers/remoteproc/imx_rproc.h

@@ -22,6 +22,8 @@ enum imx_rproc_method {
 	IMX_RPROC_MMIO,
 	/* Through ARM SMCCC */
 	IMX_RPROC_SMC,
+	/* Through System Control Unit API */
+	IMX_RPROC_SCU_API,
 };
 
 struct imx_rproc_dcfg {