etnaviv: blt: use only for tiling, and add missing formats

etnaviv: blt: use only for tiling, and add missing formats

* Removes the incorrect usage of translate_rs_format
* Disables use of BLT engine for different src/dst format

We only really need the BLT engine for tiling/detiling right now, but it
would be nice to support as many blit cases as possible to avoid using PE
for that.

To deal with different formats we need to:
 * Have a translate_blt_format which has all supported formats
 * Fix the swizzle translation from gallium (current version was wrong)
 * Set the src/dst sRGB bits as needed
 * Find which type conversions the BLT engine can actually do

Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>