Correct the GCC GenFw and ld flag to build PRM run time modules. These changes are made for X64 GCC compiler, current present for AARCH64 only. Adds addition _X64_OBJCOPY_STRIPFLAG for X64 to retain required symbol during objcopy. Signed-off-by: Abdul Lateef Attar <AbdulLateef.Attar@amd.com>