[U-Boot] Falcon mode boot support

[Andy Pont]

Hi Tom,

> How big is the args file?  We default to placing the args at 0x88000000
> in ti_am335x_common.h (see CONFIG_SYS_SPL_ARGS_ADDR) to make sure that
> we don't have an overlap between the DT and the kernel which is quite
> possible with a reasonably sized DT and placing it at 0x80000100.

Changing the CONFIG_SYS_SPL_ARGS_ADDR to be the same as the value in the ti_
am335x_common.h header file seems to have fixed the issue.

Unfortunately it hasn't improved the boot time by much - the bulk of the
time seems to be in reading and decompressing the kernel from SPI flash
device (Spansion S25FL164).  The only other storage medium on the board is
an eMMC flash device - would putting the kernel in there give a faster boot
time?

Thanks,

Andy.