mb/google/dedede: add mainboard_smi_espi_handler for dedede.

By adding mainboard_smi_espi_handler, the espi smi can be handled
properly.

BUG=b:163382105
TEST=Tested lid close smi can be handled properly in depthcharge stage

Signed-off-by: Kane Chen <kane.chen@intel.com>
Change-Id: I8a2ecb52d5f6586f8acd57c4965b4238b95e3b64
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44564
Reviewed-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-by: Maulik V Vaghela <maulik.v.vaghela@intel.com>
Reviewed-by: Dtrain Hsu <dtrain_hsu@compal.corp-partner.google.com>
Reviewed-by: Aamir Bohra <aamir.bohra@intel.com>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/dedede/smihandler.c

@@ -36,3 +36,8 @@ void elog_gsmi_cb_mainboard_log_wake_source(void)
 {
 	google_chromeec_log_events(MAINBOARD_EC_LOG_EVENTS | MAINBOARD_EC_S0IX_WAKE_EVENTS);
 }
+
+void mainboard_smi_espi_handler(void)
+{
+	chromeec_smi_process_events();
+}