platform/rdfremontcfg1: enable bl1 based boot flow

TF-A support booting from BL1 instead of BL31. With this flow, BL2 would
be loading the required images. Hence pre-loading of BL31, NT FW config
BL33 and RMM images are not required.

Signed-off-by: Vijayenthiran Subramaniam <vijayenthiran.subramaniam@arm.com>
Change-Id: Ife67dd3269670988126ef2815fb5eb4000159fdf