lavc/flacdsp: optimise RVV vector type for lpc32

This is pretty much the same as for lpc16, though it only improves half
as large prediction orders. With 128-bit vectors, this gives:

   C      V old  V new
1   69.2  181.5   95.5
2  107.7  180.7   95.2
3  145.5  180.0  103.5
4  183.0  179.2  102.7
5  220.7  178.5  128.0
6  257.7  194.0  127.5
7  294.5  193.7  126.7
8  331.0  193.0  126.5

Larger prediction orders see no significant changes at that size.

0 files changed, 0 insertions, 0 deletions