feat(libtl): add TPM event log management helpers

Introduce `tpm_event_log.c` and `tpm_event_log.h` to simplify managing
the TPM event log within a Transfer List. These helpers allow:

- Extending an existing event log entry in-place if possible
- Adding a new event log TE if needed, while preserving old data
- Finalizing and resizing the TE after log writing is complete

This isolates common event log handling logic used during measured boot,
making integration simpler across different firmware stages.

Change-Id: I5506b4a7111ae690e1c9032bb245618a16fb1fff
Signed-off-by: Harrison Mutai <harrison.mutai@arm.com>
diff --git a/CMakeLists.txt b/CMakeLists.txt
index a1bd03f..d5a9f12 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -23,6 +23,7 @@
 add_library(tl
     STATIC
         ${PROJECT_SOURCE_DIR}/src/generic/transfer_list.c
+        ${PROJECT_SOURCE_DIR}/src/generic/tpm_event_log.c
         ${PROJECT_SOURCE_DIR}/src/generic/logging.c
 )