libpayload: Add commonlib/bsd/elog and its dependency

Add commonlib/bsd/elog dependency in libpayload. This will allow other
payloads (e.g. depthcharge) to implement their own eventlog read and
write utilities.

Also include commonlib/bsd/elog.c source to libc-srcs. This ensure
payloads could utilize commonlib elog helper functions.

Change-Id: I64d0fdd2a8eff1d89a1ac451d37b61787b5564e7
Signed-off-by: Hsuan Ting Chen <roccochen@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63115
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
Reviewed-by: Julius Werner <jwerner@chromium.org>

payloads/libpayload/include/libpayload.h

@@ -45,6 +45,7 @@
 #include <stdbool.h>
 #include <libpayload-config.h>
 #include <cbgfx.h>
+#include <commonlib/bsd/elog.h>
 #include <commonlib/bsd/fmap_serialized.h>
 #include <commonlib/bsd/helpers.h>
 #include <commonlib/bsd/mem_chip_info.h>

payloads/libpayload/libc/Makefile.inc

@@ -39,3 +39,7 @@ libc-$(CONFIG_LP_LIBC) += die.c
 libc-$(CONFIG_LP_LIBC) += coreboot.c
 libc-$(CONFIG_LP_LIBC) += fmap.c
 libc-$(CONFIG_LP_LIBC) += fpmath.c
+
+ifeq ($(CONFIG_LP_LIBC),y)
+libc-srcs += $(coreboottop)/src/commonlib/bsd/elog.c
+endif