When configuring the IPU for packed YUV 4:2:2, depending on the scaling
ratios given by the source and destination resolutions, it is possible
to crash the IPU block, to the point where a software reset of the IP
does not fix it. This can happen anytime, in the first few frames, or
after dozens of minutes. The same crash also happens when the IPU is
fully controlled by the LCD controller (in that case no HW register is
written at any moment after startup), which points towards a hardware
bug.

Thanksfully multiplanar YUV is not affected.

Until this bug is fixed or worked around, address this issue by removing
support for YUV 4:2:2 on the IPU of the JZ4725B.

v2: Update commit message (remove the "crash beyond repair" bit)
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20200730144830.10479-3-paul@crapouillou.net