riscv: add HAVE_SYSCALL_TRACEPOINTS to Kconfig

I looked into Documentation/trace/ftrace-design.rst and, I think,
we check all the boxes needed for HAVE_SYSCALL_TRACEPOINTS.
Signed-off-by: NDavid Abdurachmanov <david.abdurachmanov@gmail.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

arch/riscv/Kconfig

@@ -34,6 +34,7 @@ config RISCV
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_PERF_EVENTS
+	select HAVE_SYSCALL_TRACEPOINTS
 	select IRQ_DOMAIN
 	select RISCV_ISA_A if SMP
 	select SPARSE_IRQ