MDEV-33447 fixup: pmem_persist() on RISC-V and LoongArch

Let us enable pmem_persist() on RISC-V and LoongArch, because those are
available in the Debian CI.
In commit 3f9f5ca these were initially
disabled by default.

According to the available documentation, these instructions are
available in all ISA versions. On LoongArch there would also be
__builtin_loongarch_dbar() that generates the same code.

storage/innobase/CMakeLists.txt

@@ -49,7 +49,7 @@ IF(UNIX)
       LINK_LIBRARIES(numa)
     ENDIF()
     IF(CMAKE_SIZEOF_VOID_P EQUAL 8)
-      IF(CMAKE_SYSTEM_PROCESSOR MATCHES "(aarch|AARCH|p(ower)?pc|x86_|amd)64")
+      IF(CMAKE_SYSTEM_PROCESSOR MATCHES "(aarch|AARCH|p(ower)?pc|x86_|amd|loongarch|riscv)64")
         OPTION(WITH_INNODB_PMEM "Support memory-mapped InnoDB redo log" ON)
       ELSE() # Disable by default on ISA that are not covered by our CI
         OPTION(WITH_INNODB_PMEM "Support memory-mapped InnoDB redo log" OFF)