mmc: core: Don't return an error for CD/WP GPIOs when GPIOLIB is unset

When CONFIG_GPIOLIB is unset, its stubs will return -ENOSYS. That means
when the mmc core parses DT for CD/WP GPIOs via mmc_of_parse(), -ENOSYS
becomes propagated to the caller. Typically this means that the mmc host
driver fails to probe.

As the CD/WP GPIOs are already treated as optional, let's extend that to
cover the case when CONFIG_GPIOLIB is unset.

Reported-by: Michal Simek <michal.simek@xilinx.com>
Fixes: 16b23787fc70 ("mmc: sdhci-of-arasan: Call OF parsing for MMC")
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Venu Byravarasu <vbyravarasu@nvidia.com>

drivers/mmc/core/host.c

@@ -457,7 +457,7 @@ int mmc_of_parse(struct mmc_host *host)
 					   0, &cd_gpio_invert);
 		if (!ret)
 			dev_info(host->parent, "Got CD GPIO\n");
-		else if (ret != -ENOENT)
+		else if (ret != -ENOENT && ret != -ENOSYS)
 			return ret;
 
 		/*
@@ -481,7 +481,7 @@ int mmc_of_parse(struct mmc_host *host)
 	ret = mmc_gpiod_request_ro(host, "wp", 0, false, 0, &ro_gpio_invert);
 	if (!ret)
 		dev_info(host->parent, "Got WP GPIO\n");
-	else if (ret != -ENOENT)
+	else if (ret != -ENOENT && ret != -ENOSYS)
 		return ret;
 
 	if (of_property_read_bool(np, "disable-wp"))