timestamps: Rename timestamps to make names more consistent

This patch aims to make timestamps more consistent in naming,
to follow one pattern. Until now there were many naming patterns:
- TS_START_*/TS_END_*
- TS_BEFORE_*/TS_AFTER_*
- TS_*_START/TS_*_END
This change also aims to indicate, that these timestamps can be used
to create time-ranges, e.g. from TS_BOOTBLOCK_START to TS_BOOTBLOCK_END.

Signed-off-by: Jakub Czapiga <jacz@semihalf.com>
Change-Id: I533e32392224d9b67c37e6a67987b09bf1cf51c6
Reviewed-on: https://review.coreboot.org/c/coreboot/+/62019
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
Reviewed-by: Raul Rangel <rrangel@chromium.org>

src/lib/decompressor.c

@@ -23,8 +23,8 @@ struct bootblock_arg arg = {
 	.base_timestamp = 0,
 	.num_timestamps = 2,
 	.timestamps = {
-		{ .entry_id = TS_START_ULZ4F },
-		{ .entry_id = TS_END_ULZ4F },
+		{ .entry_id = TS_ULZ4F_START },
+		{ .entry_id = TS_ULZ4F_END },
 	},
 };