emulators/rpcs3: unbreak on aarch64 after ee309cdf

rpcs3/Emu/Cell/PPUThread.cpp:713:19: error: no member named 'r32' in 'asmjit::arm::Gp'
                                c.ldr(args[1].r32(), arm::ptr(imm_address));
                                      ~~~~~~~ ^

Reported by:	pkg-fallout

(cherry picked from commit 6fe03357)