ARM: dts: imx27-phytec-phycard-s-som: Rename file to .dtsi

PCA-100 module cannot be used standalone. This patch renames
module file to .dtsi and excludes it from compilation.

Signed-off-by: Alexander Shiyan <[e-mail]>
Signed-off-by: Shawn Guo <[e-mail]>

arch/arm/boot/dts/Makefile

···
 	imx27-apf27dev.dtb \
 	imx27-pdk.dtb \
 	imx27-phytec-phycore-rdk.dtb \
-	imx27-phytec-phycard-s-som.dtb \
 	imx27-phytec-phycard-s-rdk.dtb \
 	imx31-bug.dtb \
 	imx35-eukrea-mbimxsd35-baseboard.dtb \

arch/arm/boot/dts/imx27-phytec-phycard-s-rdk.dts

···
  * http://www.gnu.org/copyleft/gpl.html
  */
 
-#include "imx27-phytec-phycard-s-som.dts"
+#include "imx27-phytec-phycard-s-som.dtsi"
 
 / {
 	model = "Phytec pca100 rapid development kit";