Drop global ddrphy_trained_csr which maybe different with per board
ddrphy_trained_csr. DDR TOOL generates ddrphy_trained_csr for each
board, using the global ddrphy_trained_csr has risk that values may
be not up to date.

Signed-off-by: Peng Fan <peng.fan@nxp.com>

Use the new symbol to refer to any 'SPL' build, including TPL and VPL

Signed-off-by: Simon Glass <sjg@chromium.org>

Since i.MX9 uses same DDR PHY with i.MX8M, split the DDRPHY to a common
directory under imx, then use dedicated ddr controller driver for each
iMX9 and iMX8M.

The DDRPHY registers are space compressed, so it needs conversion to
access the DDRPHY address. Introduce a common PHY address remap function
for both iMX8M and iMX9 for all PHY registers accessing.

Signed-off-by: Ye Li <ye.li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>