AR9331: little endian arch support

Is it possible to build a working little endian image for AR9331 based modules?

The SoC is supported

ToH

Can you help me interpret which part of the table you present indicates little endian support?

There is no little endian support for ar9331, ath79 is big endian (only). Yes, mips technically could run in either endianess, but theory and practice are different stories. You can expect a world of pain, should you even try to change that (driver/ kernel bugs, bootloader oddities, and much more),

While it should be theoretically possible, you really don't want to go there.