Because there is no BL2, BL31 must determine the entrypoint and memory
location of BL32 and BL33 on its own.

BL32_BASE and PRELOADED_BL33_BASE will be set in the corresponding board
makefile. We also allow a DTB address to be specified for cases when BL33
is a Linux image.

NOTE: It is possible to pull in this information from device tree as
well, however libfdt does not contain the required hooks to make this
happen at this point in time.

Signed-off-by: Benjamin Fair <b-fair@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Andrew F. Davis <afd@ti.com>