radeon: lower texture memory consumption is some cases

radeon: lower texture memory consumption is some cases

When searching for valid miptree check images in range
of [BaseLeve, MaxLevel] not [MinLod, MaxLoad].
Prevents unnecessary miptree allocations in cases when during
every rendering operation different texture image level
was selected using MIN_LOD = MAX_LOD = level (for every level
new miptree for whole texture was allocated).

Candidate for 7.8 branch.

Signed-off-by: Maciej Cencora <m.cencora@gmail.com>