arm64: dts: phycore-imx8mm: Correction in gpio-line-names

Remove unused nINT_ETHPHY entry from gpio-line-names in gpio1 nodes of
phyCORE-i.MX8MM and phyBOARD-Polis-i.MX8MM devicetrees.

Fixes: ae6847f2 ("arm64: dts: freescale: Add phyBOARD-Polis-i.MX8MM support")
Signed-off-by: Yashwanth Varakala <y.varakala@phytec.de>
Signed-off-by: Cem Tenruh <c.tenruh@phytec.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>