86xx: Fix GUR PCI config registers properly.

Back in commit 975a083a where
I tried to "8610HPCD: Fix typos in two PCI setup registers", I
botched it due to not realizing that 8610 and 8641 had different
Global Utility Register defintions, one of which was like 85xx,
and the other wasn't.  Correct this problem by introducing two
symbols, one for each 86xx SoC, but neither of which is named
anything like 85xx.

My bad.  Lovely Wednesday with git bisect.  You know.

Signed-off-by: Jon Loeliger <jdl@freescale.com>