coresight: syscfg: Add initial configfs support

Adds configfs subsystem and attributes to the configuration manager
to enable the listing of loaded configurations and features.

The default values of feature parameters can be accessed and altered
from these attributes to affect all installed devices using the feature.

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mike Leach <[email protected]>
Signed-off-by: Mathieu Poirier <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: mikel-armbb

drivers/hwtracing/coresight/Kconfig

@@ -8,6 +8,7 @@ menuconfig CORESIGHT
 	depends on OF || ACPI
 	select ARM_AMBA
 	select PERF_EVENTS
+	select CONFIGFS_FS
 	help
 	  This framework provides a kernel interface for the CoreSight debug
 	  and trace drivers to register themselves with. It's intended to build

drivers/hwtracing/coresight/Makefile

@@ -5,7 +5,8 @@
 obj-$(CONFIG_CORESIGHT) += coresight.o
 coresight-y := coresight-core.o  coresight-etm-perf.o coresight-platform.o \
 		coresight-sysfs.o coresight-syscfg.o coresight-config.o \
-		coresight-cfg-preload.o coresight-cfg-afdo.o
+		coresight-cfg-preload.o coresight-cfg-afdo.o \
+		coresight-syscfg-configfs.o
 obj-$(CONFIG_CORESIGHT_LINK_AND_SINK_TMC) += coresight-tmc.o
 coresight-tmc-y := coresight-tmc-core.o coresight-tmc-etf.o \
 		      coresight-tmc-etr.o