soc: j784s4: update firmware data load address

SYSFW has made available an additional 2KB for the boardcfg data used
for combined boot flow. This extra memory for TIFS boardcfg entries
would facilitate additional security related features.

Signed-off-by: Hari Nagalla <hnagalla@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>