serial: fdt: add device tree support for pl01x

This patch adds device tree support for arm pl010/pl011 driver.

Signed-off-by: Vikas Manocha <vikas.manocha@st.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/doc/device-tree-bindings/serial/pl01x.txt b/doc/device-tree-bindings/serial/pl01x.txt
new file mode 100644
index 0000000..61c27d1
--- /dev/null
+++ b/doc/device-tree-bindings/serial/pl01x.txt
@@ -0,0 +1,7 @@
+* ARM AMBA Primecell PL011 & PL010 serial UART
+
+Required properties:
+- compatible: must be "arm,primecell", "arm,pl011" or "arm,pl010"
+- reg: exactly one register range with length 0x1000
+- clock: input clock frequency for the UART (used to calculate the baud
+  rate divisor)