powerpc/85xx: Fix Wrong PCIe 3 virtual address on corenet_ds platforms

powerpc/85xx: Fix Wrong PCIe 3 virtual address on corenet_ds platforms

This patch fixes a wrong address define in corenet_ds.h (used by
P4080DS.h, P3041DS.h, P5020DS.h).

Since board/Freescale/corenet_ds/tlb.c does not use the
CONFIG_SYS_PCIE3_MEM_VIRT define (uses CONFIG_SYS_PCIE1_MEM_VIRT with a
fix offset instead) this has no effect to the functionality. But it may
be important for changes in the future?

Signed-off-by: Ralf Trübenbach <ralf.truebenbach@men.de>
Cc: Andy Fleming <afleming@gmail.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>