CVE-2023-52494: Out-of-bounds Write

In the Linux kernel, the following vulnerability has been resolved:

bus: mhi: host: Add alignment check for event ring read pointer

Though we do check the event ring read pointer by "is_valid_ring_ptr" to make sure it is in the buffer range, but there is another risk the pointer may be not aligned. Since we are expecting event ring elements are 128 bits(struct mhi_ring_element) aligned, an unaligned read pointer could lead to multiple issues like DoS or ring buffer memory corruption.

So add a alignment check for event ring read pointer.