mmc: sdhci-iproc: Do not define 'struct acpi_device_id' when !CONFIG_ACPI

Since ACPI_PTR() is used to NULLify the value when !CONFIG_ACPI,
'struct sdhci_iproc_acpi_ids' becomes defined but unused.

Fixes the following W=1 kernel build warning:

 mmc/host/sdhci-iproc.c:297:36: warning: ‘sdhci_iproc_acpi_ids’ defined but not used [-Wunused-const-variable=]

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Scott Branden <scott.branden@broadcom.com>
Link: https://lore.kernel.org/r/20200707064701.GC3500@dellSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-iproc.c

@@ -294,12 +294,14 @@ static const struct of_device_id sdhci_iproc_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, sdhci_iproc_of_match);
 
+#ifdef CONFIG_ACPI
 static const struct acpi_device_id sdhci_iproc_acpi_ids[] = {
 	{ .id = "BRCM5871", .driver_data = (kernel_ulong_t)&iproc_cygnus_data },
 	{ .id = "BRCM5872", .driver_data = (kernel_ulong_t)&iproc_data },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(acpi, sdhci_iproc_acpi_ids);
+#endif
 
 static int sdhci_iproc_probe(struct platform_device *pdev)
 {