init: Enable SWD/GDB with WFI in debug builds.
build: Change release build define.

* Change using release build define to just defined or not defined.
* Enable WFI in project configs.
* Define SZ for ChibiOS 2.6.4.
gdb: Add gdbinit.

Usage:
arm-none-eabi-gdb -x gdbinit build/tracker.elf
Tracker: Enable WFI.
gsm: Increase buffer size for server error msgs.
Tracker: Fine tune configuration.