refactor(arm): simplify early platform setup function in BL2

Refactor `arm_bl2_early_platform_setup` to accept generic u_register_t
values, enabling support for firmware handoff boot arguments in
common code. This simplifies the interface for early platform setup.

Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
Change-Id: Ie0dbe4d32bbef22bd185fdafe50091a2ea5f550f
6 files changed