coresight: tmc: mark symbols static where possible

We get a few warnings when building kernel with W=1:
drivers/hwtracing/coresight/coresight-tmc-etr.c:23:6: warning: no previous prototype for 'tmc_etr_enable_hw' [-Wmissing-prototypes]
drivers/hwtracing/coresight/coresight-tmc-etf.c:25:6: warning: no previous prototype for 'tmc_etb_enable_hw' [-Wmissing-prototypes]
drivers/hwtracing/coresight/coresight-tmc.c:250:9: warning: no previous prototype for ‘trigger_cntr_show’ [-Wmissing-prototypes]
...

In fact, these functions are only used in the file in which they are
declared and don't need a declaration, but can be made static.
so this patch marks these functions with 'static'.
Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwtracing/coresight/coresight-tmc-etf.c

@@ -22,7 +22,7 @@
 #include "coresight-priv.h"
 #include "coresight-tmc.h"
 
-void tmc_etb_enable_hw(struct tmc_drvdata *drvdata)
+static void tmc_etb_enable_hw(struct tmc_drvdata *drvdata)
 {
 	CS_UNLOCK(drvdata->base);
 

drivers/hwtracing/coresight/coresight-tmc-etr.c

@@ -20,7 +20,7 @@
 #include "coresight-priv.h"
 #include "coresight-tmc.h"
 
-void tmc_etr_enable_hw(struct tmc_drvdata *drvdata)
+static void tmc_etr_enable_hw(struct tmc_drvdata *drvdata)
 {
 	u32 axictl;
 

drivers/hwtracing/coresight/coresight-tmc.c

@@ -247,7 +247,7 @@ static struct attribute *coresight_tmc_mgmt_attrs[] = {
 	NULL,
 };
 
-ssize_t trigger_cntr_show(struct device *dev,
+static ssize_t trigger_cntr_show(struct device *dev,
 				 struct device_attribute *attr, char *buf)
 {
 	struct tmc_drvdata *drvdata = dev_get_drvdata(dev->parent);