ARM: tegra: seaboard: add missing DT vendor prefixes

A couple devices' DT compatible values only contained the device name
without any vendor prefix. Add the missing vendor prefixes.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>

arch/arm/boot/dts/tegra20-seaboard.dts

@@ -523,12 +523,12 @@ regulator@14 {
 		};
 
 		temperature-sensor@4c {
-			compatible = "nct1008";
+			compatible = "onnn,nct1008";
 			reg = <0x4c>;
 		};
 
 		magnetometer@c {
-			compatible = "ak8975";
+			compatible = "ak,ak8975";
 			reg = <0xc>;
 			interrupt-parent = <&gpio>;
 			interrupts = <109 0x04>; /* gpio PN5 */