drm/i2c: tda998x: add some basic mode validation
drm/i2c: tda998x: add some basic mode validation

The TDA998x can't handle modes with clocks above 150MHz, or resolutions
larger than 8192x2048.

Signed-off-by: Russell King <f6aa0246ff943bfa8602cdf60d40c481b38ed232@arm.linux.org.uk>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs