riscv: mm: Do not restrict mmap address based on hint

The hint address should not forcefully restrict the addresses returned
by mmap as this causes mmap to report ENOMEM when there is memory still
available.

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Fixes: b5b4287a ("riscv: mm: Use hint address in mmap if available")
Fixes: add2cc6b ("RISC-V: mm: Restrict address space for sv39,sv48,sv57")
Closes: https://lore.kernel.org/linux-kernel/ZbxTNjQPFKBatMq+@ghost/T/#mccb1890466bf5a488c9ce7441e57e42271895765
Link: https://lore.kernel.org/r/20240826-riscv_mmap-v1-3-cd8962afe47f@rivosinc.com


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