kdbus: porting to to 5.4

kdbus: porting to to 5.4

The following changes were made to adapt kdbus driver to 5.4 kernel

- use KERNEL_DS instead of get_ds()
- remove ITER_KVEC flag
- remove 'type' argument from access_ok()
- use memfd_fcntl() instead of shmem_get_seals()
- use uapi/linux/mount.h

Fixes: 736706bee329 ("get rid of legacy 'get_ds()' function")
Fixes: aa563d7bca6e ("iov_iter: Separate type from direction and use accessor functions")
Fixes: 96d4f267e40f ("Remove 'type' argument from access_ok() function")
Fixes: 5aadc431a593 ("shmem: rename functions that are memfd-related")
Fixes: 5d752600a8c3 ("mm: restructure memfd code")
Fixes: e262e32d6bde ("vfs: Suppress MS_* flag defs within the kernel unless explicitly enabled")
Change-Id: I8d2b3db1c83bb21114554ba9eb38e5e439f5c141
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>