dt-bindings: phy: mediatek,hdmi-phy: Fix clock output names for MT8195

For all of the HDMI PHYs compatible with the one found on MT8195
the output clock has a different datasheet name and specifically
it is called "hdmi_txpll", differently from the older HDMI PHYs
which output block is called "hdmitx_dig_cts".

Replace clock output name string check by max item number one to allow
the new name on all of the HDMI PHY IPs that are perfectly compatible
with MT8195.

[Louis-Alexis Eyraud: split patch, addressed previous feedback from
mailing list, and reworded description]

Fixes: c78fe548b062 ("dt-bindings: phy: mediatek: hdmi-phy: Add mt8195 compatible")
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Louis-Alexis Eyraud <louisalexis.eyraud@collabora.com>
Link: https://patch.msgid.link/20251217-mtk-genio-evk-hdmi-support-v2-1-a994976bb39a@collabora.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>