To avoid unnecessary pollution of the global symbol namespace move the
driver core exports into their own namespace and import that into the two
bus modules.

For more info see https://lwn.net/Articles/760045/Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20220116180535.2367780-10-jic23@kernel.org