soc/amd/picasso: initialize ACP device at init() time

soc/amd/picasso: initialize ACP device at init() time

The ACP device sits behind a bridge. Despite the logs indicating
the bridge is likely hooked up, there's some unusual behavior of
writes not sticking. Aside from the speculation of what's causing
the issues the initialization of the device should occur at init()
because of these potential dependencies.

BUG=b:155882600

Change-Id: I8fa83d7d1d4f356c56971d4175a2ae6497a92fb8
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/42231
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>