OMAP3: PM: Add prepare idle and resume idle call for uart4

Add prepare idle and resume idle call for uart4 used by 3630.
Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

arch/arm/mach-omap2/pm34xx.c

@@ -388,6 +388,7 @@ void omap_sram_idle(void)
 	/* PER */
 	if (per_next_state < PWRDM_POWER_ON) {
 		omap_uart_prepare_idle(2);
+		omap_uart_prepare_idle(3);
 		omap2_gpio_prepare_for_idle(per_next_state);
 		if (per_next_state == PWRDM_POWER_OFF)
 				omap3_per_save_context();
@@ -459,6 +460,7 @@ void omap_sram_idle(void)
 		if (per_prev_state == PWRDM_POWER_OFF)
 			omap3_per_restore_context();
 		omap_uart_resume_idle(2);
+		omap_uart_resume_idle(3);
 	}
 
 	/* Disable IO-PAD and IO-CHAIN wakeup */