util: Add optional gdbinit for EC debugging
util: Add optional gdbinit for EC debugging

This gdbinit sets up useful functions and initialization
for EC debugging.

BRANCH=none
BUG=none
TEST=ln -s util/gdbinit .gdbinit
     Tested debugging on stm32h743.
TEST=make BOARD=nocturne_fp
     BOARD=nocturne_fp GDBSERVER=openocd GDBPORT=3333 gdb
     # Check that the right object files were added

Change-Id: I0e15501832d4e65e8779aee2c0dc8ca170fa5f3c
Signed-off-by: Craig Hesling <383db090fd8ef907a606ac8a9eccd2962bc489cf@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1856380
Reviewed-by: Harry Cutts <1d9acf085666736c25fb5139ba37ad9d917ae7f5@chromium.org>
Reviewed-by: Aseda Aboagye <12c9b286316a940fd31c24070da5ab64cdd4d0e7@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec