ARM: mach-k3: sysfw-loader: Copy sysfw.itb to OCRAM in OSPI/SPI bootmode

In case of xSPI bootmode OSPI flash is in DDR mode and needs to be accessed
in multiple of 16bit accesses Hence we cannot parse sysfw.itb FIT image
directly on OSPI flash via MMIO window. So, copy the image to internal
on-chip RAM before parsing the image.

Moreover, board cfg data maybe modified by ROM/TIFS in case of HS platform
and thus cannot reside in OSPI/xSPI and needs to be copied over to
internal OCRAM.

This unblocks OSPI/xSPI boot on HS platforms

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Dave Gerlach <d-gerlach@ti.com>
Tested-by: Keerthy <j-keerthy@ti.com>
Acked-by: Pratyush Yadav <p.yadav@ti.com>