feat(handoff): enhance transfer list library

Define new transfer entry TL_TAG_OPTEE_PAGABLE_PART for OP-TEE.
Add API for achieving handoff args from transfer entries.
Add API for dumping the transfer list.
Add tl->flags, tl->reserved and TL_FLAGS_HAS_CHECKSUM to align to
the spec update.
Update TL signature to 4a0f_b10b to align to the spec update.
Minor fixes for the coding and comment style.

Change-Id: I0e159672e4ef4c50576f70b82e1b7bae08407acc
Signed-off-by: Raymond Mao <raymond.mao@linaro.org>
2 files changed