This effectively reverts:

| commit f9df22b
| Author: Alexander Shiyan <shc_work@mail.ru>
| Date:   Mon Oct 8 10:35:04 2012 +0400
|
|    Add more generated files to .gitignore

barebox* is not limited to the toplevel directory, so this ignores
all files starting with 'barebox' from which we have several we do
not wish to ignore. Add barebox-flash-image to the ignore list which
seemed to be the motivation for the original patch.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Alexander Shiyan <shc_work@mail.ru>