target: armv8_dpm: silence error on register R/W

The command 'gdb_report_register_access_error' is used to silence
errors while reading registers and not reporting them to GDB.
Nevertheless, the error is printed by a LOG_ERROR() in armv8_dpm.

Change the message to LOG_DEBUG().
It will still cause the error to be propagated and eventually
printed by the caller (e.g. by the command 'reg').

Change-Id: Ic0db74fa28235d686ddd21a5960c52ae003e0931
Signed-off-by: Antonio Borneo <[email protected]>
Reviewed-on: https://review.openocd.org/c/openocd/+/8267
Tested-by: jenkins

src/target/armv8_dpm.c

@@ -677,7 +677,7 @@ static int dpmv8_read_reg(struct arm_dpm *dpm, struct reg *r, unsigned regnum)
 	}
 
 	if (retval != ERROR_OK)
-		LOG_ERROR("Failed to read %s register", r->name);
+		LOG_DEBUG("Failed to read %s register", r->name);
 
 	return retval;
 }
@@ -719,7 +719,7 @@ static int dpmv8_write_reg(struct arm_dpm *dpm, struct reg *r, unsigned regnum)
 	}
 
 	if (retval != ERROR_OK)
-		LOG_ERROR("Failed to write %s register", r->name);
+		LOG_DEBUG("Failed to write %s register", r->name);
 
 	return retval;
 }