Brightness of imx/LVDS can be adjusted with PWM or GPIO (signal: display data 9)

Right now we have no interface for this in Embox, but in future the following code
can be used:

	REG32_STORE(0x20e0194, 0x5);
	gpio_setup_mode(3, (0x1 << 30), GPIO_MODE_OUTPUT);
	gpio_set(3, (0x1 << 30), 1); /* Turn on */
	gpio_set(3, (0x1 << 30), 0); /* Turn off */
