riscv/ftrace: Add RECORD_MCOUNT support

Now recordmcount.pl recognizes RISC-V object files. For the mechanism to
work, we have to disable the linker relaxation.

Cc: Greentime Hu <[email protected]>
Signed-off-by: Alan Kao <[email protected]>
Signed-off-by: Palmer Dabbelt <[email protected]>
3 files changed