UPSTREAM: mb/google/poppy/variant/nami - Ensure power cycle of FPMCU on startup

Add functionality to ensure that the FPMCU is power cycled long enough
on boot to ensure proper reset.

This solution relies solely on coreboot to sequence the power and reset
signals appropriately (150ms on boot).

-Confirmed power is off for 150ms on boot.
-Confirmed RCC_CSR of FPMCU indicates power cycle occurred.
-Confirmed reset is de-asserted approx 3ms after power application
(target >2.5ms)

BUG=b:245954151
TEST=Confirmed FPMCU is still functional on Nami and timings are
as expected.

(cherry picked from commit d1211cb3de2546480cc1179262d31fed9e1eea9a)

Original-Change-Id: I0a23bda96bc2ea90be81a2310605f75c55c0a839
Original-Signed-off-by: Tarun Tuli <taruntuli@google.com>
Original-Reviewed-on: https://review.coreboot.org/c/coreboot/+/73212
Original-Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Original-Reviewed-by: Subrata Banik <subratabanik@google.com>
Original-Reviewed-by: Shelley Chen <shchen@google.com>
Original-Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
GitOrigin-RevId: d1211cb3de2546480cc1179262d31fed9e1eea9a
Change-Id: I8a1229fd92e99c5f67ca20df812f84388b47bd3f
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/coreboot/+/4493687
Commit-Queue: Tarun Tuli <taruntuli@google.com>
Auto-Submit: Tarun Tuli <taruntuli@google.com>
Reviewed-by: Shelley Chen <shchen@chromium.org>
Tested-by: Tarun Tuli <taruntuli@google.com>
2 files changed