EDAC: Replace EDAC_DIMM_PTR() macro with edac_get_dimm() function

The EDAC_DIMM_PTR() macro takes 3 arguments from struct mem_ctl_info.
Clean up this interface to only pass the mci struct and replace this
macro with a new function edac_get_dimm().

Also introduce an edac_get_dimm_by_index() function for later use.
This allows it to get a DIMM pointer only by a given index. This can
be useful if the DIMM's position within the layers of the memory
controller or the exact size of the layers are unknown.

Small style changes made for some hunks after applying the semantic
patch.

Semantic patch used:

@@ expression mci, a, b,c; @@

-EDAC_DIMM_PTR(mci->layers, mci->dimms, mci->n_layers, a, b, c)
+edac_get_dimm(mci, a, b, c)

 [ bp: Touchups. ]

Signed-off-by: Robert Richter <rrichter@marvell.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Cc: Tero Kristo <t-kristo@ti.com>
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20191106093239.25517-2-rrichter@marvell.com