brcmfmac: fix invalid access to struct acpi_device fields

The fields of struct acpi_device are only known when CONFIG_ACPI is
defined. Fix this by using a helper function. This will resolve the
issue found in linux-next:

 ../brcmfmac/bcmsdh.c: In function 'brcmf_ops_sdio_probe':
 ../brcmfmac/bcmsdh.c:1139:7: error: dereferencing pointer to incomplete type
   adev->flags.power_manageable = 0;
       ^

Fixes: f0992ace ("brcmfmac: prohibit ACPI power management ...")
Cc: Fu, Zhonghui <zhonghui.fu@linux.intel.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/brcm80211/brcmfmac/bcmsdh.c

@@ -1117,6 +1117,18 @@ MODULE_DEVICE_TABLE(sdio, brcmf_sdmmc_ids);
 static struct brcmfmac_sdio_platform_data *brcmfmac_sdio_pdata;
 
 
+static void brcmf_sdiod_acpi_set_power_manageable(struct device *dev,
+						  int val)
+{
+#if IS_ENABLED(CONFIG_ACPI)
+	struct acpi_device *adev;
+
+	adev = ACPI_COMPANION(dev);
+	if (adev)
+		adev->flags.power_manageable = 0;
+#endif
+}
+
 static int brcmf_ops_sdio_probe(struct sdio_func *func,
 				const struct sdio_device_id *id)
 {
@@ -1124,7 +1136,6 @@ static int brcmf_ops_sdio_probe(struct sdio_func *func,
 	struct brcmf_sdio_dev *sdiodev;
 	struct brcmf_bus *bus_if;
 	struct device *dev;
-	struct acpi_device *adev;
 
 	brcmf_dbg(SDIO, "Enter\n");
 	brcmf_dbg(SDIO, "Class=%x\n", func->class);
@@ -1132,11 +1143,9 @@ static int brcmf_ops_sdio_probe(struct sdio_func *func,
 	brcmf_dbg(SDIO, "sdio device ID: 0x%04x\n", func->device);
 	brcmf_dbg(SDIO, "Function#: %d\n", func->num);
 
-	/* prohibit ACPI power management for this device */
 	dev = &func->dev;
-	adev = ACPI_COMPANION(dev);
-	if (adev)
-		adev->flags.power_manageable = 0;
+	/* prohibit ACPI power management for this device */
+	brcmf_sdiod_acpi_set_power_manageable(dev, 0);
 
 	/* Consume func num 1 but dont do anything with it. */
 	if (func->num == 1)