fix: Fix vpaddq for VLEN !=128

[camel-cdr]

Turns out the vaddq changes in my last PR (#397) only work for VLEN=128, sorry.
I've reverted the changes, and added only the narrow instead of compress back in.
This now passes on qemu with all VLENs.

However the following functions still fail with VLEN=256:

Test vtbl1_s8                       failed
Test vtbl1_u8                       failed
Test vtbl2_s8                       failed
Test vtbl2_u8                       failed
Test vtbl3_s8                       failed
Test vtbl3_u8                       failed
Test vtbl4_s8                       failed
Test vtbl4_u8                       failed

Test vzipq_s8                       failed
Test vzipq_s16                      failed
Test vzipq_s32                      failed
Test vzipq_f32                      failed
Test vzipq_u8                       failed
Test vzipq_u16                      failed
Test vzipq_u32                      failed

Test vuzpq_s8                       failed
Test vuzpq_s16                      failed
Test vuzpq_s32                      failed
Test vuzpq_f32                      failed
Test vuzpq_u8                       failed
Test vuzpq_u16                      failed
Test vuzpq_u32                      failed

Test vst3_f32                       failed

[howjmay]

for vlen != 128 I have opened an issue(#375), just I am busy for other things now.
Always more than happy for your help