tests: cmsis_dsp: MVE correlate out-of-bounds access workaround

The MVE `arm_correlate_f32` and `arm_correlate_q31` implementations may
write to negative indices of the output buffer (refer to the upstream
CMSIS-DSP bug ARM-software/CMSIS-DSP#59).

This commit adds a workaround for the above bug by overallocating the
output buffer memory and offsetting the output buffer supplied to the
function.

Revert this commit when this bug is fixed.

Signed-off-by: Stephanos Ioannidis <stephanos.ioannidis@nordicsemi.no>