The file 'adi-ad9265-fmc-125ebz.dtsi' seems to be missing form the most recent image file for the SD card (6 February 2015 release, Zynq & Altera SoC Quick Start Guide [Analog Devices Wiki]). Can you provide a link to this file? Also, are these files present in the GIT repository?
Here is the answer:
1) Yes the .dtsi files are controlled by the Linux repository.
2) When they are committed, they are committed to this location: linux/arch/arm/boot/dts
3) Branch 2014_R2 has the required file adi-ad9265-fmc-125ebz.dtsi, though there is an error in the initial comment section (it says 'Analog Devices AD9265-FMC-500EBZ FPGA FMC Card' instead of 'Analog Devices AD9265-FMC-125EBZ FPGA FMC Card'.