soc/mediatek: Add mtk_pcie_deassert_perst for early PCIe reset

Even we assert PRSET# early to save the delay between PERST# assertion
and de-assertion. MediaTek PCIe driver still takes 47ms waiting for PCIe
link up. (1ms delay for each try)

```
[INFO ]  mtk_pcie_domain_enable: PCIe link up success (47 tries)
```

Refactor common/pcie.c and add mtk_pcie_deassert_perst for early PCIe
reset. So we can de-assert PERST# at early stage to improve the boot
time.

BUG=b:361728592
TEST=emerge-cherry coreboot

Change-Id: I008e95263bfaf0119353382c2d2ce5ce29c6a382
Signed-off-by: Yidi Lin <yidilin@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/84117
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jianjun Wang <jianjun.wang@mediatek.com>

0 files changed, 0 insertions, 0 deletions