freedreno/a7xx: Update TPL1_DBG_ECO_CNTL1 to fix UBWC corruption

What does this MR do and why?

Copying UBWC image via BLIT_OP_SCALE may be corrupted if previously someone copied image with bit 18 set in TPL1_DBG_ECO_CNTL1.

Found by replaying blob's cmdstream on a740, but somehow this issue doesn't happen on Android.