Stuck at "Starting Kernel..."

I ran into a similar problem and I ended up taking the angstrom-socfpga (Yocto) release, built the entire image and then started tinkering with the device tree. I never had much luck in porting the Qsys tree to DTB, especially with custom logic attached to the HPS. For me taking the home-build standard using cyclone5-defconfig, or something like that, and modify it to fit your new design works best. I remember having problems with Watchdog timers that where put in the device tree by the sopc2dts tool but were actually lacking in h/w causing trace dumps just like yours.