pinctrl: sprd: fix off by one bugs

info->groups[] has info->ngroups elements so these comparisons should be
>= instead of >.

Fixes: 41d32cfc ("pinctrl: sprd: Add Spreadtrum pin control driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Baolin Wang <baolin.wang@spreadtrum.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>