libcommon-cs: move a_reset.c into libbsc

a_reset.c was originally used by both libmsc and libbsc in the old openbsc.git
repository. Now osmo-msc.git has its own copy, and the idea of sharing
libcommon-cs is no longer applicable. Move it to libbsc where it belongs.

Change-Id: I30e4b5dab9c6d761d20a3a0e5b9ec2d65e64ebc5
3 files changed