init-install: add timeout for legacy grub
After installing an image from an iso, booting the system using
the legacy boots makes the grub prompt wait for an enter.
This is not desirable since many of this devices are embedded
devices that should start by them self without user entry.
(From OE-Core rev:
f6d85426e48d458d0835d4fd3314ce53ab92bd38)
Signed-off-by: Catalin Enache <catalin.enache@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
