sgi/install_prerequisites.sh: install openssl version 3.0

Starting from TF-A v2.7, OpenSSL 3.0 is required in order to compile the
host tools (fiptool, cert_create, encrypt_fw). Add functions to install
openssl 3.0.2 library.

Change-Id: Ie03af474f7871b8bed4e3db35e053c14fc3890b1
Signed-off-by: Tony K Nadackal <tony.nadackal@arm.com>