drm/imagination: Add firmware trace to debugfs

Firmware trace is exposed at /sys/debug/dri/<dev_nr>/pvr_fw/trace_0.
Trace is enabled via the group mask at
/sys/debug/dri/<dev_nr>/pvr_params/fw_trace_mask.

Changes since v8:
- Corrected license identifiers

Changes since v3:
- Use drm_dev_{enter,exit}

Co-developed-by: Matt Coster <matt.coster@imgtec.com>
Signed-off-by: Matt Coster <matt.coster@imgtec.com>
Signed-off-by: Sarah Walker <sarah.walker@imgtec.com>
Signed-off-by: Donald Robson <donald.robson@imgtec.com>
Link: https://lore.kernel.org/r/009cf9fee347fa96c8a665dc368fc54a5ffceff0.1700668843.git.donald.robson@imgtec.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>

drivers/gpu/drm/imagination/pvr_device.c

@@ -5,6 +5,7 @@
 #include "pvr_device_info.h"
 
 #include "pvr_fw.h"
+#include "pvr_params.h"
 #include "pvr_power.h"
 #include "pvr_queue.h"
 #include "pvr_rogue_cr_defs.h"
@@ -495,6 +496,14 @@ pvr_device_init(struct pvr_device *pvr_dev)
 	struct device *dev = drm_dev->dev;
 	int err;
 
+	/*
+	 * Setup device parameters. We do this first in case other steps
+	 * depend on them.
+	 */
+	err = pvr_device_params_init(&pvr_dev->params);
+	if (err)
+		return err;
+
 	/* Enable and initialize clocks required for the device to operate. */
 	err = pvr_device_clk_init(pvr_dev);
 	if (err)