The MediaTek MT8173 comes with a PowerVR Rogue GX6250, which is one
of the Series6XT GPUs, another sub-family of the Rogue family.
This was part of the very first few versions of the PowerVR submission,
but was later dropped. The compatible string has been updated to follow
the new naming scheme adopted for the AXE series.
In a previous iteration of the PowerVR binding submission [1], the
number of clocks required for the 6XT family was mentioned to be
always 3. This is also reflected here.
[1] https://lore.kernel.org/dri-devel/6eeccb26e09aad67fb30ffcd523c793a43c79c2a.camel@xxxxxxxxxx/
Signed-off-by: Chen-Yu Tsai <wenst@xxxxxxxxxxxx>