msm: adsprpc: FastRPC driver interface to get HLOS PID

Currently there is no interface request to get HLOS PID of
the device attached to FastRPC bus driver. Add new request
FASTRPC_DEV_GET_HLOS_PID, to get HLOS PID of the attached
device.

Signed-off-by: Himateja Reddy <quic_hmreddy@quicinc.com>

include/linux/fastrpc.h

@@ -18,6 +18,7 @@ enum fastrpc_driver_status {
 enum fastrpc_driver_invoke_nums {
 	FASTRPC_DEV_MAP_DMA = 1,
 	FASTRPC_DEV_UNMAP_DMA,
+	FASTRPC_DEV_GET_HLOS_PID,
 };
 
 /**
@@ -44,6 +45,14 @@ struct fastrpc_dev_unmap_dma {
 	size_t size;
 };
 
+/**
+ * struct fastrpc_dev_get_hlos_pid - fastrpc dma buffer unmap structure
+ * @hlos_pid   : HLOS PID of attached device
+ */
+struct fastrpc_dev_get_hlos_pid {
+	int hlos_pid;
+};
+
 /**
  * fastrpc_device - device that belong to the fastrpc bus
  * @hn: Head node to add to fastrpc device list