arm64: dts: amlogic: gx: correct hdmi clocks

arm64: dts: amlogic: gx: correct hdmi clocks

The clocks provided to HDMI tx are not consistent between gx and g12:
* gx receives the peripheral clock as 'isfr' while g12 receives it as
  'iahb'
* g12 gets the HDMI system clock as 'isfr' but gx does not even get it.
  It surely needs that clock since the driver is directly poking around
  the clock controller's registers for that clock.

Align gx SoCs with g12 and provide:
 * the HDMI peripheral clock as 'iahb'
 * the HDMI system clock as 'isfr'

Fixes: 6939db7e0dbf ("ARM64: dts: meson-gx: Add support for HDMI output")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20240626152733.1350376-2-jbrunet@baylibre.com
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>