dm: led: add BCM6328 led driver

This driver is a simplified version of linux/drivers/leds/leds-bcm6328.c,
simplified to remove HW leds and blink fallbacks.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/led/Kconfig b/drivers/led/Kconfig
index 309372a..dc19f4f 100644
--- a/drivers/led/Kconfig
+++ b/drivers/led/Kconfig
@@ -9,6 +9,17 @@
 	  can provide access to board-specific LEDs. Use of the device tree
 	  for configuration is encouraged.
 
+config LED_BCM6328
+	bool "LED Support for BCM6328"
+	depends on LED && ARCH_BMIPS
+	help
+	  This option enables support for LEDs connected to the BCM6328
+	  LED HW controller accessed via MMIO registers.
+	  HW blinking is supported and up to 24 LEDs can be controlled.
+	  All LEDs can blink at the same time but the delay is shared, which
+	  means that if one LED is set to blink at 100ms and then a different
+	  LED is set to blink at 200ms, both will blink at 200ms.
+
 config LED_BLINK
 	bool "Support LED blinking"
 	depends on LED