dts: mec172x: pinctrl fixes

Two issues:

- The nsmi_gpio107 node is being defined twice with the same pinmux
  property value. This is an error when compiling the file with dtc.
  Zephyr's dtlib doesn't currently error out on this, but it will soon.

  Fix this by removing one of the redundant definitions.

- The eeprom_clk_gpio117 node label is referring to a node named
  gpspi_clk_gpio117, which is already defined in the same file, but
  with a different pinmux property value. This looks like a clear
  copy/paste error causing invalid pinmux settings for the
  gpspi_clk_gpio117 node.

  Fix it by aligning the node name with the node label to create
  a separate node with its own pinmux value.

Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>