avcodec/jpeg2000dwt: merge rescaling with interleave in 9/7 float IDWT

10% faster

Reviewed-by: Nicolas BERTRAND <nicoinattendu@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/jpeg2000dwt: merge rescaling with interleave in 9/7 int IDWT

Tha fate tests change because the edge mirroring was wrong before this commit

Reviewed-by: Nicolas BERTRAND <nicoinattendu@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>