RDMA: Do not used __packed in uapi headers

__packed is not available in linux/types.h, so we cannot use it in
the uapi headers.

The construction struct ABC {} __packed; may still compile even if
__packed is not defined, however it simply creates a variable called
__packed, and doesn't set the alignment.

All these uses of packed are on structs that already have aligned
members.

While use in hfi may indicate the struct itself is unaligned,
the use in ocrdma is on a UHW struct which should never be unaligned,
so just delete it there.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>