util/ec_parse_panicinfo: Add help message
util/ec_parse_panicinfo: Add help message

BRANCH=none
BUG=b:176500425
TEST=make BOARD=dartmonkey -j
     ./build/dartmonkey/util/ec_parse_panicinfo --help
     ./build/dartmonkey/util/ec_parse_panicinfo # Ctrl-D
     # Ensure it complains that "Panic data too short".

Signed-off-by: Craig Hesling <383db090fd8ef907a606ac8a9eccd2962bc489cf@chromium.org>
Change-Id: I32bfb0b027cf51f9f17df774cba45abe6c03b5bc
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3048643
Commit-Queue: Aseda Aboagye <12c9b286316a940fd31c24070da5ab64cdd4d0e7@chromium.org>
Reviewed-by: Patryk Duda <6aed17a362577cf10cb5675888c1635d522769c1@semihalf.com>
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