pinctrl: qcom: fix masking of pinmux functions

The following commit introduced a regression by not properly masking the
calculated value.

Fixes: 47a01ee9 ("pinctrl: qcom: Clear all function selection bits")
Signed-off-by: John Crispin <john@phrozen.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Stephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/qcom/pinctrl-msm.c

@@ -156,7 +156,7 @@ static int msm_pinmux_set_mux(struct pinctrl_dev *pctldev,
 	spin_lock_irqsave(&pctrl->lock, flags);
 
 	val = readl(pctrl->regs + g->ctl_reg);
-	val &= mask;
+	val &= ~mask;
 	val |= i << g->mux_bit;
 	writel(val, pctrl->regs + g->ctl_reg);