GitLab

1. Necessary changes to platform makefile to include fw_config
device tree and package it in fip.bin

2. Removed hw_config node from fw_config dts as there is no
HW_CONFIG device tree source for sgm775

3. Added mbedtls_heap related properties for TBBR functionality

Change-Id: I26b940c65b17ad2fb5537141f8649785bb0fd4ad
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>