mb/google/mancomb: Fix EC SCI configuration

This change fixes two problems:
1) We had the enum values for .direction and .level swapped. The naming
is very confusing...
2) ESPI_SYS is not a good event to use for EC SCI. It is a level/low
event that is only cleared by reading the eSPI status register 0x9C.
Cezanne has added a new event source that directly exposes the SCI bit.
This is the correct event source to use for EC SCI.
This same patch was added for Guybrush at CB:52673

BUG=b:186045622, b:181139095
TEST=Build

Signed-off-by: Martin Roth <martinroth@chromium.org>
Change-Id: Iac86d2ef5bdd21fbb0a0d4e235efe4fe621023b2
Reviewed-on: https://review.coreboot.org/c/coreboot/+/52948
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/mancomb/ec.c

@@ -9,10 +9,10 @@
 
 static const struct sci_source espi_sci_sources[] = {
 	{
-		.scimap = SMITYPE_ESPI_SYS,
+		.scimap = SMITYPE_ESPI_SCI_B,
 		.gpe = EC_SCI_GPI,
-		.direction = SMI_SCI_LVL,
-		.level = SMI_SCI_LVL_HIGH
+		.direction = SMI_SCI_LVL_HIGH, /* enum smi_sci_lvl */
+		.level = SMI_SCI_EDG, /* enum smi_sci_dir */
 	}
 };