EDAC/ie31200: Fix the size of EDAC_MC_LAYER_CHIP_SELECT layer

EDAC/ie31200: Fix the size of EDAC_MC_LAYER_CHIP_SELECT layer

The EDAC_MC_LAYER_CHIP_SELECT layer pertains to the rank, not the DIMM.
Fix its size to reflect the number of ranks instead of the number of DIMMs.
Also delete the unused macros IE31200_{DIMMS,RANKS}.

Fixes: 7ee40b897d18 ("ie31200_edac: Introduce the driver")
Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Tested-by: Gary Wang <gary.c.wang@intel.com>
Link: https://lore.kernel.org/r/20250310011411.31685-2-qiuxu.zhuo@intel.com