EDAC, pnd2: Fix ioremap() size in dnv_rd_reg()

Depending on how BIOS has marked the reserved region containing the 32KB
MCHBAR you can get warnings like:

resource sanity check: requesting [mem 0xfed10000-0xfed1ffff], which spans more than reserved [mem 0xfed10000-0xfed17fff]
caller dnv_rd_reg+0xc8/0x240 [pnd2_edac] mapping multiple BARs

Not all of the mmio regions used in dnv_rd_reg() are the same size.  The
MCHBAR window is 32KB and the sideband ports are 64KB.  Pass the correct
size to ioremap() depending on which resource we're reading from.

Signed-off-by: Stephen Douthit <stephend@silicom-usa.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>