w1: Add 1-Wire uclass

We might want to use 1-Wire devices connected on boards such as EEPROMs in
U-Boot.

Provide a framework to be able to do that.

Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
[eugen.hristev@microchip.com: reworked]
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
diff --git a/drivers/w1/Makefile b/drivers/w1/Makefile
new file mode 100644
index 0000000..f81693b
--- /dev/null
+++ b/drivers/w1/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_W1) += w1-uclass.o