platforms/rdv3cfg2: fix RESET_TO_BL31 params

Since RSE loads the SCP and MCP RAM firmware images during runtime,
preloading them is redundant. Additionally, as Hafnium is not enabled
on RDv3Cfg2, preloading the Hafnium and StMM images is also unnecessary.
Consequently, the preload parameters for these images have been removed.

Signed-off-by: Rakshit Goyal <rakshit.goyal@arm.com>
Change-Id: I24fdd3cf32f5977150da784ab66d7f0c5d6e3227