mmc: sdhci-pxav2: add optional core clock

Add ability to have an optional core clock just like the pxav3 driver.
The PXA168 needs this because its SDHC controllers have separate core
and io clocks that both need to be enabled. This also correctly matches
the documented devicetree bindings for this driver.
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Doug Brown <doug@schmorgal.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20230116194401.20372-6-doug@schmorgal.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-pxav2.c

@@ -191,7 +191,7 @@ static int sdhci_pxav2_probe(struct platform_device *pdev)
 	const struct sdhci_pxa_variant *variant;
 
 	int ret;
-	struct clk *clk;
+	struct clk *clk, *clk_core;
 
 	host = sdhci_pltfm_init(pdev, NULL, 0);
 	if (IS_ERR(host))
@@ -214,6 +214,13 @@ static int sdhci_pxav2_probe(struct platform_device *pdev)
 		goto free;
 	}
 
+	clk_core = devm_clk_get_optional_enabled(dev, "core");
+	if (IS_ERR(clk_core)) {
+		ret = PTR_ERR(clk_core);
+		dev_err_probe(dev, ret, "failed to enable core clock\n");
+		goto disable_clk;
+	}
+
 	host->quirks = SDHCI_QUIRK_BROKEN_ADMA
 		| SDHCI_QUIRK_BROKEN_TIMEOUT_VAL
 		| SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN;