Do I have to install Hexagon DSP SDK to run a snpe Application on dsp?
The SDk is to develop the app. Which release are you running?
kernel version=5.2.0
snpe-1.37.0
dsp-3.4.2
Look at https://github.com/96boards/documentation/wiki/Dragonboard-Hexagon-DSP, there are some instructions for this.