RDMA/bnxt_re: Using vmalloc requires including vmalloc.h

Add it

Fixes: 0c4dcd60 ("RDMA/bnxt_re: Refactor hardware queue memory allocation")
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>