ata: ahci_platform: Add synopsys ahci controller in DT's compatible list

SPEAr13xx series of SoCs contain Synopsys AHCI SATA Controller which shares
ahci_platform driver with other controller versions.

This patch updates DT compatible list for ahci_platform. It also updates and
renames binding documentation to more generic name.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/Documentation/devicetree/bindings/ata/ahci-platform.txt b/Documentation/devicetree/bindings/ata/ahci-platform.txt
new file mode 100644
index 0000000..8bb8a76
--- /dev/null
+++ b/Documentation/devicetree/bindings/ata/ahci-platform.txt
@@ -0,0 +1,16 @@
+* AHCI SATA Controller
+
+SATA nodes are defined to describe on-chip Serial ATA controllers.
+Each SATA controller should have its own node.
+
+Required properties:
+- compatible        : compatible list, contains "calxeda,hb-ahci" or "snps,spear-ahci"
+- interrupts        : <interrupt mapping for SATA IRQ>
+- reg               : <registers mapping>
+
+Example:
+        sata@ffe08000 {
+		compatible = "calxeda,hb-ahci";
+                reg = <0xffe08000 0x1000>;
+                interrupts = <115>;
+        };