nb/intel/sandybridge: Restore `mainboard_early_init()` call

Commit 7a874330919a4df9cc5b66058b4340465b7ea041 (mb/google,samsung: Drop
init_bootmode_straps()) got rid of the `mainboard_early_init()` function
call and weak definition in Sandy Bridge code. However, this function is
still used by several Sandy Bridge mainboards, so bring back the dropped
call and weak definition.

The aforementioned commit did not cause any build-time errors because it
did not remove the `mainboard_early_init()` function declaration.

Change-Id: I82768e9a187696d42b61be44d4aa048acc19d551
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63515
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>

0 files changed, 0 insertions, 0 deletions