arm: mach-k3: Move J721s2 SPL init functions to mach-k3

This matches AM64 and J721e and removes the need to forward
declare k3_spl_init(), k3_mem_init(), and check_rom_loaded_sysfw()
in sys_proto.h.

Signed-off-by: Andrew Davis <afd@ti.com>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>
3 files changed