When the vaddr parameter passed to map_region() is not aligned to the page directory,
it causes incorrect address mapping for later regions.
For example, in the sv32 case, `PGPOOL` started at `0x80a00000` with a size of `1024*4096B`,
leading to page table errors for the range `0x80c00000~0x80e00000`.
This patch fixes the issue by ensuring map_region() correctly handles unaligned vaddr cases.
Signed-off-by: wushenhui <wushenhui@xiaomi.com>
9653e5d6d7