Documentation: dt-bindings: reformat and order list of ahci-platform compatibles

The ahci-platform.txt Device Tree binding documentation is gaining a
growing number of compatible strings, and it will gain one more with
the addition of the Marvell Armada 380 AHCI support. It is therefore
time to reformat this list into a proper bullet list, and more
importantly order it alphabetically;

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Tejun Heo <tj@kernel.org>

Documentation/devicetree/bindings/ata/ahci-platform.txt

@@ -4,10 +4,14 @@ SATA nodes are defined to describe on-chip Serial ATA controllers.
 Each SATA controller should have its own node.
 
 Required properties:
-- compatible        : compatible list, one of "snps,spear-ahci",
-                      "snps,exynos5440-ahci", "ibm,476gtr-ahci",
-                      "allwinner,sun4i-a10-ahci", "fsl,imx53-ahci"
-                      "fsl,imx6q-ahci" or "snps,dwc-ahci"
+- compatible        : compatible string, one of:
+  - "allwinner,sun4i-a10-ahci"
+  - "fsl,imx53-ahci"
+  - "fsl,imx6q-ahci"
+  - "ibm,476gtr-ahci"
+  - "snps,dwc-ahci"
+  - "snps,exynos5440-ahci"
+  - "snps,spear-ahci"
 - interrupts        : <interrupt mapping for SATA IRQ>
 - reg               : <registers mapping>