Benjamin Herrenschmidt 6aadad5a75 spi: Add booting from flash to litedram init
It will look for an ELF binary at the flash offset specified
for the board (currently 0x300000 on Arty but that could be
changed).

Note: litedram is regenerated in order to rebuild the init code,
which was done using a newer version of litedram from LiteX.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
..
litedram-initmem.vhdl litedram: Fix DRAM init mem using too many address bits
litedram_core.init spi: Add booting from flash to litedram init
litedram_core.v spi: Add booting from flash to litedram init