hw21/26: optimize extension module powerup

Enable extension module power in first state loader.
Reasoning: Unpowered module can block I2C bus.

board/nm/nmhw21/board.c

@@ -794,7 +794,7 @@ static void init_bd_spl(void)
 	}
 }
 
-static void power_um(void)
+static void power_um(void) 
 {
 	int bus;
 
@@ -1071,6 +1071,10 @@ static void init_usb_hub(void)
 
 static void init_user_module(void)
 {
+	int bus;
+
+	bus = da9063_claim_i2c_bus();
+
 	puts("UM:    ");
 
 	REQUEST_AND_CLEAR_GPIO(GPIO_RST_UM_N);		/* Assert reset (active low) */
@@ -1079,6 +1083,8 @@ static void init_user_module(void)
 	gpio_direction_input(GPIO_RST_UM_N);		/* Release reset (open drain) */
 	mdelay(10);
 
+	da9063_release_i2c_bus(bus);
+
 	mdelay(200);					/* Give module some time to boot */
 	um_init(CONFIG_UM_I2C_BUS);			/* Try to detect user module */