EDAC: constantify the struct bus_type usage

EDAC: constantify the struct bus_type usage

In many places in the edac code, struct bus_type pointers are passed
around and then eventually sent to the driver core, which can handle a
constant pointer.  So constantify all of the edac usage of these as well
because the data in them is never modified by the edac code either.

Cc: Borislav Petkov <bp@alien8.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: James Morse <james.morse@arm.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Robert Richter <rric@kernel.org>
Cc:  <linux-edac@vger.kernel.org>
Link: https://lore.kernel.org/r/2023121909-tribute-punctuate-4b22@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>