cosmetic: remove code duplication

The ARM and the X86 implementation of the conversion functions share
the same, non cpu specific implementation in separate files.

This commit removes the code duplication by putting the generic
implementation into a convert_base.c, similar to to convolve_base.c

Change-Id: Ic8d8534a343e27cde79ddc85be4998ebd0cb6e5c
5 files changed