perf: hisi: Constify static struct attribute_group

The only usage is to put their addresses in an array of pointers to
const struct attribute group. Make them const to allow the compiler
to put them in read-only memory.
Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Link: https://lore.kernel.org/r/20210117212847.21319-4-rikard.falkeborn@gmail.comSigned-off-by: Will Deacon <will@kernel.org>

drivers/perf/hisilicon/hisi_uncore_ddrc_pmu.c

@@ -319,7 +319,7 @@ static struct attribute *hisi_ddrc_pmu_identifier_attrs[] = {
 	NULL
 };
 
-static struct attribute_group hisi_ddrc_pmu_identifier_group = {
+static const struct attribute_group hisi_ddrc_pmu_identifier_group = {
 	.attrs = hisi_ddrc_pmu_identifier_attrs,
 };
 

drivers/perf/hisilicon/hisi_uncore_hha_pmu.c

@@ -331,7 +331,7 @@ static struct attribute *hisi_hha_pmu_identifier_attrs[] = {
 	NULL
 };
 
-static struct attribute_group hisi_hha_pmu_identifier_group = {
+static const struct attribute_group hisi_hha_pmu_identifier_group = {
 	.attrs = hisi_hha_pmu_identifier_attrs,
 };
 

drivers/perf/hisilicon/hisi_uncore_l3c_pmu.c

@@ -321,7 +321,7 @@ static struct attribute *hisi_l3c_pmu_identifier_attrs[] = {
 	NULL
 };
 
-static struct attribute_group hisi_l3c_pmu_identifier_group = {
+static const struct attribute_group hisi_l3c_pmu_identifier_group = {
 	.attrs = hisi_l3c_pmu_identifier_attrs,
 };