soc/intel/apollolake: Enable logging for wake sources in S0ix

This change adds GSMI callback elog_gsmi_cb_platform_log_wake_source
to enable wake source logging from S0ix on APL/GLK. Additionally,
elog.c is added to smm stage.

BUG=b:79449585
TEST=Verified that S0ix entry/exit events are added to eventlog:

=========== Power button ============
59 | 2018-06-25 14:01:11 | S0ix Enter
60 | 2018-06-25 14:01:30 | S0ix Exit
61 | 2018-06-25 14:02:00 | Wake Source | Power Button | 0

=========== Lid open ================
62 | 2018-06-25 14:02:36 | S0ix Enter
63 | 2018-06-25 14:02:56 | S0ix Exit
64 | 2018-06-25 14:03:26 | Wake Source | GPE # | 15
65 | 2018-06-25 14:03:32 | Wake Source | GPE # | 65
66 | 2018-06-25 14:03:37 | EC Event | Lid Open

=========== Trackpad ================
67 | 2018-06-25 14:04:20 | S0ix Enter
68 | 2018-06-25 14:04:33 | S0ix Exit
69 | 2018-06-25 14:05:03 | Wake Source | GPE # | 15
70 | 2018-06-25 14:05:08 | Wake Source | GPE # | 66

Change-Id: I005de58c73d00dc9d7e64f1459f6d786792b94db
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/27234
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Justin TerAvest <teravest@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
2 files changed