ARM: mach-k3: sysfw-loader: Use SPI memmapped addr when loading SYSFW

Since ROM configures OSPI controller to be in memory mapped mode in OSPI
boot, R5 SPL can directly pass the memory mapped pointer to ROM. With
this ROM can directly pull the SYSFW image from OSPI.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>