OMAP3: serial: Fix uart4 handling for 3630

This patch makes the following:
 - Adds missing wakeup padding register handling.
 - Fixes a hardcode to use PER module ONLY on UART3.
Signed-off-by: NSergio Aguirre <saaguirre@ti.com>
Signed-off-by: NGovindraj.R <govindraj.raja@ti.com>
Signed-off-by: NKevin Hilman <khilman@deeprootsystems.com>

arch/arm/mach-omap2/serial.c

@@ -487,7 +487,7 @@ static void omap_uart_idle_init(struct omap_uart_state *uart)
 	omap_uart_smart_idle_enable(uart, 0);
 
 	if (cpu_is_omap34xx()) {
-		u32 mod = (uart->num == 2) ? OMAP3430_PER_MOD : CORE_MOD;
+		u32 mod = (uart->num > 1) ? OMAP3430_PER_MOD : CORE_MOD;
 		u32 wk_mask = 0;
 		u32 padconf = 0;
 
@@ -506,6 +506,10 @@ static void omap_uart_idle_init(struct omap_uart_state *uart)
 			wk_mask = OMAP3430_ST_UART3_MASK;
 			padconf = 0x19e;
 			break;
+		case 3:
+			wk_mask = OMAP3630_ST_UART4_MASK;
+			padconf = 0x0d2;
+			break;
 		}
 		uart->wk_mask = wk_mask;
 		uart->padconf = padconf;