misc: bcm-vk: add misc device to Broadcom VK driver

Add misc device base support to create and remove devnode.
Additional misc functions for open/read/write/release/ioctl/sysfs, etc
will be added in follow on commits to allow for individual review.

Co-developed-by: Desmond Yan <desmond.yan@broadcom.com>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Desmond Yan <desmond.yan@broadcom.com>
Signed-off-by: Scott Branden <scott.branden@broadcom.com>
Link: https://lore.kernel.org/r/20210120175827.14820-5-scott.branden@broadcom.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>