tdfxfb: make use of DDC information about connected monitor
Read DDC information from a connected monitor and use it to select initial
mode (if the mode is not specified).
Also, use the information to protect against modes outside the monitor
specs.
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl> Tested-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>