syncfiles.pl: allow for multiple synced sections
syncfiles.pl: allow for multiple synced sections

Allow for multiple sections of Makefiles to be synchronized; the
intent is to use this to synchronize the Perl file generation rules.

Signed-off-by: H. Peter Anvin <8a453bad9912ffe59bc0f0b8abe03df9be19379e@zytor.com>

techkey/nasm,techkey/nasm,techkey/nasm,techkey/nasm,techkey/nasm