UPSTREAM: PCI: rockchip: remove the pointer to L1 substate cap

UPSTREAM: PCI: rockchip: remove the pointer to L1 substate cap

Per the errata of TRM, the RC can't support L1 substate, so we
need to remove the L1 substate cap as well as operation for
PCIE_RC_CONFIG_L1_SUBSTATE_CTRL2.

Change-Id: If3e1e7ac46720c9487724f15b22905a02bebb7ca
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Tested-by: Brian Norris <briannorris@chromium.org>
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 9d7598543b5fa2dacd7ccdffe9e03b578a9a03d1)