pinctrl: qcom: make 'm_voc_groups' static

The m_voc_groups is not declared outside of the
driver, so make it static to avoid the following
sparse wanrning:

drivers/pinctrl/qcom/pinctrl-msm8976.c:592:12: warning: symbol 'm_voc_groups' was not declared. Should it be static?

Signed-off-by: Ben Dooks (Codethink) <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Reviewed-by: Bjorn Andersson <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>

drivers/pinctrl/qcom/pinctrl-msm8976.c

···
 static const char * const qdss_traceclk_a_groups[] = {
 	"gpio46",
 };
-const char * const m_voc_groups[] = {
+static const char * const m_voc_groups[] = {
 	"gpio123", "gpio124",
 };
 static const char * const blsp_i2c5_groups[] = {