riscv: tlb: convert __p*d_free_tlb() to inline functions

This is to prepare for enabling MMU_GATHER_RCU_TABLE_FREE.
No functionality changes.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20231219175046.2496-3-jszhang@kernel.org


Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>