MAINTAINERS: update the location of the driver-core git tree

The driver core git tree has moved, so properly document it.

Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Dave Ertman <david.m.ertman@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/2025041447-showbiz-other-7130@gregkh


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