bcm53xx: drop Copyright header from two of my bash scripts

Both scripts modified by this patch were added by me. First of all I
incorrectly added OpenWrt as Copyright holder. It was wrong because:
1) I simply can't transfer my moral rights according to the Polish law
2) Transfering copyrights (economic rights) requires an agreement which
   I didn't sign with OpenWrt(.org).
Other than that I don't find these trivial scripts important enough to
put info about *my* copyrights in a header so this patch just drops them
completely.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>