[PATCH] pinctrl: mediatek: Fix multiple registeration issue.

Since our common driver need support main chip and PMU
at the same time, that means it will register two
pinctrl device, and the pinctrl_desc structure should
be used two times.

But pinctrl_desc use global static definition, then
the latest registered pinctrl device will overwrite
the old one's, all members in pinctrl_desc will set to
the new one's, such as name, pins and pins numbers, etc.
This is a bug. Changing to use devm_kzalloc to fix it.

Cc: stable at vger.kernel.org # v4.1+
Signed-off-by: Hongzhou Yang <redacted>
---
 drivers/pinctrl/mediatek/pinctrl-mtk-common.c |   27 +++++++++++++++----------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common.c b/drivers/pinctrl/mediatek/pinctrl-mtk-common.c
index ad1ea16..2bba504 100644
--- a/drivers/pinctrl/mediatek/pinctrl-mtk-common.c
+++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common.c

@@ -1202,17 +1202,12 @@ static int mtk_pctrl_build_state(struct platform_device *pdev)
        return 0;
 }

-static struct pinctrl_desc mtk_pctrl_desc = {
-       .confops        = &mtk_pconf_ops,
-       .pctlops        = &mtk_pctrl_ops,
-       .pmxops         = &mtk_pmx_ops,
-};
-
 int mtk_pctrl_init(struct platform_device *pdev,
                const struct mtk_pinctrl_devdata *data,
                struct regmap *regmap)
 {
        struct pinctrl_pin_desc *pins;
+       struct pinctrl_desc *mtk_pctrl_desc;
        struct mtk_pinctrl *pctl;
        struct device_node *np = pdev->dev.of_node, *node;
        struct property *prop;

@@ -1265,12 +1260,22 @@ int mtk_pctrl_init(struct platform_device *pdev,

        for (i = 0; i < pctl->devdata->npins; i++)
                pins[i] = pctl->devdata->pins[i].pin;
-       mtk_pctrl_desc.name = dev_name(&pdev->dev);
-       mtk_pctrl_desc.owner = THIS_MODULE;
-       mtk_pctrl_desc.pins = pins;
-       mtk_pctrl_desc.npins = pctl->devdata->npins;
+
+       mtk_pctrl_desc = devm_kzalloc(&pdev->dev, sizeof(*mtk_pctrl_desc),
+                               GFP_KERNEL);
+       if (!mtk_pctrl_desc)
+               return -ENOMEM;