coresight-etm: add CoreSight ETM/PTM driver

This driver manages CoreSight ETM (Embedded Trace Macrocell) that
supports processor tracing. Currently supported version are ARM
ETMv3.x and PTM1.x.

Signed-off-by: Pratik Patel <pratikp@codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

coresight-etm3x: adding missing error checking
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/arm/Kconfig.debug

@@ -1376,5 +1376,14 @@ config CORESIGHT_SINK_ETBV10
 	  This enables support for the Embedded Trace Buffer version 1.0 driver
 	  that complies with the generic implementation of the component without
 	  special enhancement or added features.
+
+config CORESIGHT_SOURCE_ETM3X
+	bool "CoreSight Embedded Trace Macrocell 3.x driver"
+	select CORESIGHT_LINKS_AND_SINKS
+	help
+	  This driver provides support for processor ETM3.x and PTM1.x modules,
+	  which allows tracing the instructions that a processor is executing
+	  This is primarily useful for instruction level tracing.  Depending
+	  the ETM version data tracing may also be available.
 endif
 endmenu