edac: core fix to use dynamic kobject

Static kobjects are not supported in linux kernel.  Convert the
edac_pci_top_main_kobj from static to dynamic.  This avoids the double
free of the edac_pci_top_main_kobj.name that we see on module reload of
the e752x edac driver (and probably others as well).

In addition Greg KH <greg@kroah.com> has pointed out that this code may be
cleaned up significantly.  I will look at that as a follow-on patch, for
now, I just want the minimum fix to get this double-free oops bug
squashed...

Many thanks to Greg KH for his patience in showing me what the
Documentation/kobject.txt already said (oops)...

Signed-off-by: Arthur Jones <ajones@riverbed.com>
Signed-off-by: Doug Thompson <dougthompson@xmission.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>