[SERIAL] Use an enum for serial8250 platform device IDs

Rather than hard-coding the platform device IDs, enumerate them.
We don't particularly care about the actual ID we get, just as
long as they're unique.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/ppc/syslib/mpc10x_common.c

@@ -140,12 +140,12 @@ struct platform_device ppc_sys_platform_devices[] = {
 	},
 	[MPC10X_UART0] = {
 		.name = "serial8250",
-		.id	= 0,
+		.id	= PLAT8250_DEV_PLATFORM,
 		.dev.platform_data = serial_plat_uart0,
 	},
 	[MPC10X_UART1] = {
 		.name = "serial8250",
-		.id	= 1,
+		.id	= PLAT8250_DEV_PLATFORM1,
 		.dev.platform_data = serial_plat_uart1,
 	},
 

arch/ppc/syslib/mpc83xx_devices.c

@@ -165,7 +165,7 @@ struct platform_device ppc_sys_platform_devices[] = {
 	},
 	[MPC83xx_DUART] = {
 		.name = "serial8250",
-		.id	= 0,
+		.id	= PLAT8250_DEV_PLATFORM,
 		.dev.platform_data = serial_platform_data,
 	},
 	[MPC83xx_SEC2] = {

arch/ppc/syslib/mpc85xx_devices.c

@@ -282,7 +282,7 @@ struct platform_device ppc_sys_platform_devices[] = {
 	},
 	[MPC85xx_DUART] = {
 		.name = "serial8250",
-		.id	= 0,
+		.id	= PLAT8250_DEV_PLATFORM,
 		.dev.platform_data = serial_platform_data,
 	},
 	[MPC85xx_PERFMON] = {