build: Remove the old PIC/PIE patch, let libtool sort it out

build: Remove the old PIC/PIE patch, let libtool sort it out

* Remove the old change from '08 to add in PIE arguments at automake level.
  Versions of libtool since then know how to deal with -fpie and do the right
  thing according to whether its building shared or executable objects.
  So just pass '-fpie' as CFLAG and let libtool do its thing.