remoteproc: imx_rproc: add a NXP/Freescale imx_rproc driver

Provide a basic driver to control Cortex M4 co-processor found
on NXP i.MX7D and i.MX6SX.
Currently it is able to resolve addresses between M4 and main CPU,
start and stop the co-processor. Other functionality is not provided
or test.

This driver was tested on NXP i.MX7D and expected to work on
i.MX6SX as well.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

drivers/remoteproc/Kconfig

@@ -12,6 +12,15 @@ config REMOTEPROC
 
 if REMOTEPROC
 
+config IMX_REMOTEPROC
+	tristate "IMX6/7 remoteproc support"
+	depends on SOC_IMX6SX || SOC_IMX7D
+	help
+	  Say y here to support iMX's remote processors (Cortex M4
+	  on iMX7D) via the remote processor framework.
+
+	  It's safe to say N here.
+
 config OMAP_REMOTEPROC
 	tristate "OMAP remoteproc support"
 	depends on HAS_DMA

drivers/remoteproc/Makefile

@@ -8,6 +8,7 @@ remoteproc-y				+= remoteproc_debugfs.o
 remoteproc-y				+= remoteproc_sysfs.o
 remoteproc-y				+= remoteproc_virtio.o
 remoteproc-y				+= remoteproc_elf_loader.o
+obj-$(CONFIG_IMX_REMOTEPROC)		+= imx_rproc.o
 obj-$(CONFIG_OMAP_REMOTEPROC)		+= omap_remoteproc.o
 obj-$(CONFIG_WKUP_M3_RPROC)		+= wkup_m3_rproc.o
 obj-$(CONFIG_DA8XX_REMOTEPROC)		+= da8xx_remoteproc.o