riscv: Fix hugetlb_mask_last_page() when NAPOT is enabled

[ Upstream commit a179a4bf ]

When NAPOT is enabled, a new hugepage size is available and then we need
to make hugetlb_mask_last_page() aware of that.

Fixes: 82a1a1f3

 ("riscv: mm: support Svnapot in hugetlb page")
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20240117195741.1926459-3-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>