[Fuchsia] Fix gen_build_defs.py to recognize device_profile sdk parts

The script was failing in new SDK because the new SDK added new part
type 'device_profile' that the script didn't recognize. Added the new
type to the list. Also fixed the error-handling code - previously it
was failing with NameError while trying to throw an exception to report
the unrecognized part type.

Change-Id: I5f9e59edf4ed1532c1ed7fd6a23007a3f11c5ecf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1664791
Commit-Queue: Sergey Ulanov <sergeyu@chromium.org>
Reviewed-by: Kevin Marshall <kmarshall@chromium.org>
Auto-Submit: Sergey Ulanov <sergeyu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#670155}