multi-arfcn, sigproc: remove unused and untested calls
multi-arfcn, sigproc: remove unused and untested calls

Index shift for convolution purposes is not needed for channelizing
and/or resampling support. When convolution is revisited for
delay and interpolation purposes, a different approach will be
used.

Signed-off-by: Thomas Tsou <7360a69f2d05d24df84c29f24b488ef8cc0e7ae2@vt.edu>

0x7678/openbts-multi-arfcn,0x7678/openbts-multi-arfcn,0x7678/openbts-multi-arfcn,0x7678/openbts-multi-arfcn,0x7678/openbts-multi-arfcn