dt-bindings: media: mtk-vcodec-encoder: fix non-vp8 clock name

dt-bindings: media: mtk-vcodec-encoder: fix non-vp8 clock name

Looking at the binding it makes sense that the `-vp8` compatible has
the `venc_lt_sel` while the other bindings have the `venc_sel` as name for
the clock.
This was also mentioned in the txt version of the binding before the
conversion:
 `
 clock-names: avc encoder must contain "venc_sel", vp8 encoder must
 contain "venc_lt_sel", decoder must contain "vcodecpll", "univpll_d2",
 `

So it is easier to check for compatible that includes vp8, since that's
just one, to have the requirement for the clock name property as
`venc_lt_sel`, rather than for all the others, some of which are missing,
thus for them, the requirement is wrongly `venc_lt_sel`.

Reordered the if/then/else to match `-vp8` and have all the rest of
the compatibles using the other clock name (`venc_sel`).

Signed-off-by: Eugen Hristev <eugen.hristev@collabora.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20231228113245.174706-3-eugen.hristev@collabora.com
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>