sam4s flash: remove unused bootstrap routine

sam4s flash: remove unused bootstrap routine

Remove the static const array containing ARM instructions for a
bootstrap program.  Despite what the comment says, the DAP can write to
the Flash and in fact this program is not referenced anywhere in openocd
so it's a bit confusing having it in there.  There should be no
functionality change from this.

Change-Id: I4ca4206f090a896628ee9b675d1f04450ada1563
Signed-off-by: Andrey Yurovsky <yurovsky@gmail.com>
Reviewed-on: http://openocd.zylin.com/1641
Tested-by: jenkins
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>