gdb: make target_auxv_parse static and rename

It is only used in auxv.c.  Also, given it is not strictly a wrapper
around target_ops::auxv (since 27a48a9223d0 "Add auxv parsing to the
architecture vector."), I think that the name prefixed with target is a
bit misleading.  Rename to just parse_auxv.

Change-Id: I41cca055b92c8ede37c258ba6583746a07d8f77e
2 files changed