ARM: mx5: board-cpuimx51.c fixup irq_to_gpio() usage

irq_to_gpio() is being called on a GPIO so change to using
gpio_to_irq() instead.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

arch/arm/mach-mx5/board-cpuimx51.c

@@ -81,7 +81,7 @@ static struct plat_serial8250_port serial_platform_data[] = {
 		.flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | UPF_IOREMAP,
 	}, {
 		.mapbase = (unsigned long)(MX51_CS1_BASE_ADDR + 0x2000000),
-		.irq = irq_to_gpio(CPUIMX51_QUARTD_GPIO),
+		.irq = gpio_to_irq(CPUIMX51_QUARTD_GPIO),
 		.irqflags = IRQF_TRIGGER_HIGH,
 		.uartclk = CPUIMX51_QUART_XTAL,
 		.regshift = CPUIMX51_QUART_REGSHIFT,