mkelfImage: set kernel_alignment so 2.6.31+ work

mkelfImage: set kernel_alignment so 2.6.31+ work

The kernel initialization code as of boot protocol 2.10 is now reading the
kernel_alignment field.  With the field left unset the kernel attempts to
align things to 4GB which is unlikely to work, so change the alignment to
the kernel's normal value of 16MB so newer kernels processed by mkelfImage
will boot.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Stefan Reinauer <stepan@coresystems.de>
Acked-by: Peter Stuge <peter@stuge.se>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@5914 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1