Introduce a PCD to control the maximum SATP mode that MMU allowed to use. This PCD helps RISC-V platform set bare or minimum SATP mode during bring up to debug memory map issue. Signed-off-by: Tuan Phan <tphan@ventanamicro.com> Reviewed-by: Dhaval Sharma <dhaval@rivosinc.com> Reviewed-by: Andrei Warkentin <andrei.warkentin@intel.com> Reviewed-by: Sunil V L <sunilvl@ventanamicro.com>