UPSTREAM: PCI: rockchip: fix wrong negotiated lanes calculation

The calculation of negotiated lanes is wrong since it should
be shifted by PCIE_CORE_PL_CONF_LANE_SHIFT, but it is shifted
by PCIE_CORE_PL_CONF_LANE_MASK. Let's fix it.

Change-Id: I164d07c86e944fdab7c1a3100c87fdd24ec0ee82
Fixes: commit e77f847df54c ("PCI: rockchip: Add Rockchip PCIe controller support")
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
(am from git.kernel.org/cgit/linux/kernel/git/next/linux-next.git
commit 898a2301cf002e1d96c0d56e41131a0d57cacb65)