I have the above device (YiFang EBM7100KLD_8G) and as there are no custom kernels for it I extracted the stock one to use in the kernel partition so I could run an oma rocks rom.  I noticed that the rotation was off (turned anti-clockwise to the left and rotating in the wrong direction).  None of Omas posted fixes would work for me.  Also I found that all rotation fixes labeled rk30 stopped any rotation, only the ones labeled rk31 did anything.

After a lot of research I found some extra lines in the stock init.rc relating to the gsensor.

write /sys/class/gsensor/yf_vendor fb=-z
write /sys/class/gsensor/yf_vendor leftright=y
write /sys/class/gsensor/yf_vendor updown=x

write /sys/class/gsensor/yf_stk831x fb=x
write /sys/class/gsensor/yf_stk831x leftright=-z
write /sys/class/gsensor/yf_stk831x updown=y

write /sys/class/gsensor/yf_mma8452 fb=x
write /sys/class/gsensor/yf_mma8452 leftright=y
write /sys/class/gsensor/yf_mma8452 updown=z

after unpacking the ramdisk boot image I have been using and inserting these lines into the init.rc my rotation issue was fixed.

I have provided some links for anyone interested.

Stock Kernel Image prepared for flashing.

Custom Ramdisk only with rotation fix for screenshot attached rom and prepared for flashing.

Stock Boot Image unaltered.

Stock build.prop with the odd tweak.

See kernel version in attached screenshot.