arm64: dts: imx8mp-evk: correct pcie pad settings

According to RM bit layout, BIT3 and BIT0 are reserved.
  8  7   6   5   4   3  2 1  0
  PE HYS PUE ODE FSEL X  DSE  X

Although function is not broken, we should not set reserved bit.

Fixes: d5065050 ("arm64: dts: imx8mp-evk: Add PCIe support")
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>