When the TF-A finishes it jumps to a hardcoded address in DRAM. We used
to put a trampoline there which brings us back to our image in SRAM.
Instead of putting a trampoline into DRAM just copy the image there
which simplifies things a bit.

Note that currently imx8_esdhc_load_piggy() uses that very same address
as a temporary buffer. This is changed in the next patch. Currently the
board is broken anyway, so we don't break bisectability.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Rouven Czerwinski <r.czerwinski@pengutronix.de>