Bump gcc from 7.1 to 7.2
Compile & run tested: ar71xx
Trace history of current patches and update with commit ref & comment
to give more clue as to why they're still around/needed. Some have
changed form since the original commit but some clue is better than no
clue at all.
Signed-off-by: Kevin Darbyshire-Bryant <kevin@darbyshire-bryant.me.uk>
Tested-by: Koen Vandeputte <koen.vandeputte@ncentric.com>