ci: update RMM build command with additional options

Refactor the build_rmm function to include more configurable options
for the RMM build process. Introduced new options such as
RMM_TOOLCHAIN, RMM_FPU_USE_AT_REL2, ATTEST_EL3_TOKEN_SIGN, and
RMM_V1_1.

Change-Id: Iff1c9205637cb8a76ac693cf3be4859ec2d19286
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
1 file changed