ARM: dts: msm: Fixup PCIe dt prefix for MPQ8092

The vendor prefix is now back to 'qcom' so fixup the MPQ8092 PCIe
dt node to use 'qcom' instead of 'qti'.

Change-Id: Ib722d4b010f67167e12d4263e2f8d13c35791b3a
Signed-off-by: Kumar Gala <galak@codeaurora.org>