misc: fastrpc: Add reserved mem support

The reserved mem support is needed for CMA heap support, which will be
used by AUDIOPD.

Co-developed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20221125071405.148786-4-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: abelvesa

drivers/misc/fastrpc.c

@@ -19,6 +19,7 @@
 #include <linux/slab.h>
 #include <linux/qcom_scm.h>
 #include <uapi/misc/fastrpc.h>
+#include <linux/of_reserved_mem.h>
 
 #define ADSP_DOMAIN_ID (0)
 #define MDSP_DOMAIN_ID (1)
@@ -2065,6 +2066,9 @@ static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev)
 		return -EINVAL;
 	}
 
+	if (of_reserved_mem_device_init_by_idx(rdev, rdev->of_node, 0))
+		dev_info(rdev, "no reserved DMA memory for FASTRPC\n");
+
 	vmcount = of_property_read_variable_u32_array(rdev->of_node,
 				"qcom,vmids", &vmids[0], 0, FASTRPC_MAX_VMIDS);
 	if (vmcount < 0)