imx8mp-venice-gw702x: Drop EQos clock workaround

The assigned-clock no longer have to be dropped, the clock are now
defined in clk-imx8mp.c and used by DWMAC driver to configure the
DWMAC clock. Drop the workarounds from U-Boot specific DT extras.

Having the clocks dropped causes the EQoS to be non-functional.

See commit c7ea9612 ("arm64: dts: imx8mp: Drop EQoS clock
workaround").

Fixes: 48c6f977 ("board: gateworks: venice: add imx8mp-gw7905-2x support")
Signed-off-by: Tim Harvey <tharvey@gateworks.com>