riscv: select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY

In commit afc76b8 ("riscv: Using PATCHABLE_FUNCTION_ENTRY instead
of MCOUNT") RISC-V added support for -fpatchable-function-entry, which
removes the need for recordmcount.

Select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY to tell the build
system not to run recordmcount.

Link: https://lore.kernel.org/linux-riscv/CAAYs2=j3Eak9vU6xbAw0zPuoh00rh8v5C2U3fePkokZFibWs2g@mail.gmail.com/T/#t
Link: https://lore.kernel.org/linux-riscv/Y4jtfrJt+%2FQ5nMOz@spud/
Signed-off-by: Song Shuai <[email protected]>
Tested-by: Guo Ren <[email protected]>
Signed-off-by: Guo Ren <[email protected]>
Acked-by: Björn Töpel <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

Author: Song Shuai

arch/riscv/Kconfig

@@ -68,6 +68,7 @@ config RISCV
 	select CPU_PM if CPU_IDLE || HIBERNATION
 	select EDAC_SUPPORT
 	select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE)
+	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE
 	select GENERIC_ARCH_TOPOLOGY
 	select GENERIC_ATOMIC64 if !64BIT
 	select GENERIC_CLOCKEVENTS_BROADCAST if SMP