m68k: virt: pass RNG seed via bootinfo block

m68k: virt: pass RNG seed via bootinfo block

This commit wires up bootinfo's RNG seed attribute so that Linux VMs can
have their RNG seeded from the earliest possible time in boot, just like
the "rng-seed" device tree property on those platforms. The link
contains the corresponding Linux patch.

Link: https://lore.kernel.org/lkml/20220626111509.330159-1-Jason@zx2c4.com/
Based-on: <20220625152318.120849-1-Jason@zx2c4.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Message-Id: <20220626111804.330745-1-Jason@zx2c4.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>