sse2: correct typos in simde_x_mm_broadcastlow_pd
sse2: correct typos in simde_x_mm_broadcastlow_pd

Correct typos:-
inpu -> input
altivec_s64 -> altivec_f64.

Also remove duplicate SIMDE_ARM_NEON_A64V8_NATIVE case.

nemequ/simde,nemequ/simde,nemequ/simde