pata-rb532-cf: get rid of the irq_to_gpio() call

The RB532 platform specific irq_to_gpio() implementation has been
removed with commit 832f5dacfa0b ("MIPS: Remove all the uses of
custom gpio.h"). Now the platform uses the generic stub which causes
the following error:

pata-rb532-cf pata-rb532-cf: no GPIO found for irq149
pata-rb532-cf: probe of pata-rb532-cf failed with error -2

Drop the irq_to_gpio() call and get the GPIO number from platform
data instead. After this change, the driver works again:

scsi host0: pata-rb532-cf
ata1: PATA max PIO4 irq 149
ata1.00: CFA: CF 1GB, 20080820, max MWDMA4
ata1.00: 1989792 sectors, multi 0: LBA
ata1.00: configured for PIO4
scsi 0:0:0:0: Direct-Access ATA CF 1GB 0820 PQ: 0\
ANSI: 5
sd 0:0:0:0: [sda] 1989792 512-byte logical blocks: (1.01 GB/971 MiB)
sd 0:0:0:0: [sda] Write Protect is off
sd 0:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't\
support DPO or FUA
sda: sda1 sda2
sd 0:0:0:0: [sda] Attached SCSI disk

Fixes: 832f5dacfa0b ("MIPS: Remove all the uses of custom gpio.h")
Cc: Alban Bedel <[e-mail]>
Cc: Ralf Baechle <[e-mail]>
Cc: Arnd Bergmann <[e-mail]>
Cc: <[e-mail]> #v4.3+
Signed-off-by: Gabor Juhos <[e-mail]>
Signed-off-by: Tejun Heo <[e-mail]>

drivers/ata/pata_rb532_cf.c

···
 #include <linux/libata.h>
 #include <scsi/scsi_host.h>
 
+#include <asm/mach-rc32434/rb.h>
+
 #define DRV_NAME	"pata-rb532-cf"
 #define DRV_VERSION	"0.1.0"
 #define DRV_DESC	"PATA driver for RouterBOARD 532 Compact Flash"
···
 	int gpio;
 	struct resource *res;
 	struct ata_host *ah;
+	struct cf_device *pdata;
 	struct rb532_cf_info *info;
 	int ret;
 
···
 		return -ENOENT;
 	}
 
-	gpio = irq_to_gpio(irq);
+	pdata = dev_get_platdata(&pdev->dev);
+	if (!pdata) {
+		dev_err(&pdev->dev, "no platform data specified\n");
+		return -EINVAL;
+	}
+
+	gpio = pdata->gpio_pin;
 	if (gpio < 0) {
 		dev_err(&pdev->dev, "no GPIO found for irq%d\n", irq);
 		return -ENOENT;