x86/platform/intel/iosf_mbi: Add a PMIC bus access notifier

x86/platform/intel/iosf_mbi: Add a PMIC bus access notifier

Some drivers may need to acquire P-Unit managed resources from interrupt
context, where they cannot call iosf_mbi_punit_acquire().

This commit adds a notifier chain which allows a driver to get notified
(in a process context) before other drivers start accessing the PMIC bus,
so that the driver can acquire any resources, which it may need during
the window the other driver is accessing the PMIC, before hand.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=155241
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: tagorereddy <tagore.chandan@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>