arm64: dts: imx: rename gpio hog as <gpio name>-hog

arm64: dts: imx: rename gpio hog as <gpio name>-hog

Rename admin_led_lower to admin-led-lower-hog.
Rename gpio rs485_en as rs485-en-hog.
Rename gpio uart4_rs485_en to uart4-rs485-en-hog.

Fix below warning:
arch/arm64/boot/dts/freescale/fsl-ls1088a-ten64.dtb: gpio@76:
  'admin_led_lower' does not match any of the regexes: '^(hog-[0-9]+|.+-hog(-[0-9]+)?)$', 'pinctrl-[0-9]+'
arch/arm64/boot/dts/freescale/imx8mm-venice-gw72xx-0x-rs232-rts.dtb:
  gpio@30230000: 'rs485_en' does not match any of the regexes: '^(hog-[0-9]+|.+-hog(-[0-9]+)?)$', 'pinctrl-[0-9]+'
arch/arm64/boot/dts/freescale/imx8mm-phygate-tauri-l-rs232-rs232.dtb:
  gpio@30220000: 'uart4_rs485_en' does not match any of the regexes: '^(hog-[0-9]+|.+-hog(-[0-9]+)?)$', 'pinctrl-[0-9]+'

Reviewed-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>