ARM: dts: DRA7: fix unit address of second PCIe instance

The unit address of the second PCIe instance
is set to be same as that of the first instance
(copy-paste error).

Fix it.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>