ARM: dts: dra7: Fix up unaligned access setting for PCIe EP

Bit positions of PCIE_SS1_AXI2OCP_LEGACY_MODE_ENABLE and
PCIE_SS1_AXI2OCP_LEGACY_MODE_ENABLE in CTRL_CORE_SMA_SW_7 are
incorrectly documented in the TRM. In fact, the bit positions are
swapped. Update the DT bindings for PCIe EP to reflect the same.

Fixes: d23f3839 ("ARM: dts: DRA7: Add pcie1 dt node for EP mode")
Cc: stable@vger.kernel.org
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>