This causes data_abort_handler from lib/unwarminder/safe_read.S to be
used instead. It allows unwarminder to avoid data aborts when
displaying the backtrace. A data_abort_handler remains in system-arm.c,
but it is not used because it is declared as a weak symbol.
Change-Id: I832066ed514347fe697e219872e90fbdd937f477
Reviewed-on: http://gerrit.rockbox.org/475
Reviewed-by: Marcin Bukat <marcin.bukat@gmail.com>
Tested-by: Boris Gjenero <boris.gjenero@gmail.com>
