feat(bl31): aarch64: RESET_TO_BL31_WITH_PARAMS

It is not always the case that RESET_TO_BL31 enabled platforms don't
execute a bootloader before BL31.

For those use cases, being able to receive arguments from that first
loader (i.e: a DTB with TPM logs) might be necessary feature.

This code has been validated on iMX8mm.

Signed-off-by: Jorge Ramirez-Ortiz <jorge@foundries.io>
Change-Id: Ibf00c3867cb1d1012b8b376e64ccaeca1c9d2bff