drm/amd/display/dc/dce110/dce110_mem_input_v: use swap macro in program_size_and_rotation

Make use of the swap macro instead of _manually_ swapping values
and remove unnecessary variable swap.

This makes the code easier to read and maintain.

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>