pinctrl: qcom: fix 'const' pointer handling

The 'tiles' array is initialized to a constant pointers to constant
strings, but the declaration is only half as constant:

drivers/pinctrl/qcom/pinctrl-qcs404.c:1660:11: error: initialization discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
drivers/pinctrl/qcom/pinctrl-sdm660.c:1417:11: error: initialization discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]

Let's make it more constant.

Fixes: 22eb8301 ("pinctrl: qcom: Add qcs404 pinctrl driver")
Fixes: a46d5e98 ("pinctrl: qcom: Support dispersed tiles")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/qcom/pinctrl-msm.h

@@ -119,7 +119,7 @@ struct msm_pinctrl_soc_data {
 	unsigned ngroups;
 	unsigned ngpios;
 	bool pull_no_keeper;
-	const char **tiles;
+	const char *const *tiles;
 	unsigned int ntiles;
 };