use fdt_kaslrseed function to de-duplicate code

use fdt_kaslrseed function to de-duplicate code

Use the fdt_kaslrseed function to deduplicate code doing the same thing.

Note that the kalsrseed command (CMD_KASLRSEED) is likely pointless now
but left in place in case boot scripts exist that rely on this command
existing and returning success. An informational message is printed to
alert users of this command that it is likely no longer needed.

Note that the Kernel's EFI STUB only relies on EFI_RNG_PROTOCOL for
randomization and completely ignores the kaslr-seed for its own
randomness needs (i.e the randomization of the physical placement of
the kernel). It gets weeded out from the DTB that gets handed over via
efi_install_fdt() as it would also mess up the measured boot DTB TPM
measurements as well.

Signed-off-by: Tim Harvey <[email protected]>
Reviewed-by: Simon Glass <[email protected]>
Cc: Michal Simek <[email protected]>
Cc: Andy Yan <[email protected]>
Cc: Akash Gajjar <[email protected]>
Cc: Ilias Apalodimas <[email protected]>
Cc: Simon Glass <[email protected]>
Cc: Patrick Delaunay <[email protected]>
Cc: Patrice Chotard <[email protected]>
Cc: Devarsh Thakkar <[email protected]>
Cc: Heinrich Schuchardt <[email protected]>
Cc: Hugo Villeneuve <[email protected]>
Cc: Marek Vasut <[email protected]>
Cc: Tom Rini <[email protected]>
Cc: Chris Morgan <[email protected]>
Acked-by: Michal Simek <[email protected]>