EDAC: Merge mci.mem_is_per_rank with mci.csbased

Both mci.mem_is_per_rank and mci.csbased denote the same thing: the
memory controller is csrows based. Merge both fields into one.

There's no need for the driver to actually fill it, as the core detects
it by checking if one of the layers has the csrows type as part of the
memory hierarchy:

	if (layers[i].type == EDAC_MC_LAYER_CHIP_SELECT)
			per_rank = true;

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>