mb/google/rex: Enable asynchronous End-Of-Post

Set the `SOC_INTEL_CSE_SEND_EOP_ASYNC' flag to request End-Of-Post
right after PCI enumeration and handle the command response at
`BS_PAYLOAD_BOOT'.

With these settings we have observed a boot time reduction of about
100ms on google/rex.

TEST=Tests on google/rex with `SOC_INTEL_CSE_SEND_EOP_ASYNC' show
End-Of-Post after PCI initialization and EOP message received at
`BS_PAYLOAD_BOOT'.

Change-Id: I27b540eeddcada521eba91fcc51504831d6dc855
Signed-off-by: Subrata Banik <subratabanik@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/74562
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kapil Porwal <kapilporwal@google.com>

0 files changed, 0 insertions, 0 deletions