linux on riscv can now detect unaligned accesses support for both vector and scalar respectively, so, it's good split AvoidUnalignedAccesses flag as Scalar and Vector flags.
https://github.com/torvalds/linux/commit/1f5288874de776412041022607513ffac74ae1a6
https://github.com/torvalds/linux/commit/d1703dc7bc8ec7adb91f5ceaf1556ff1ed212858