Comment # 10 on bug 908747 from Takashi Iwai

Then it's the result of the recent "fix".  The driver became more strict and
prunes the invalid modes for DVI.  Some monitors allow higher clocks than
specification (like yours), but these are filtered out now.

As a workaround, you can still add the mode manually via xrandr, and use it
explicitly.  For example,

% cvt -r 2560 1440
# 2560x1440 59.95 Hz (CVT 3.69M9-R) hsync: 88.79 kHz; pclk: 241.50 MHz
Modeline "2560x1440R"  241.50  2560 2608 2640 2720  1440 1443 1448 1481 +hsync
-vsync

% xrandr --newmode "2560x1440" 241.50  2560 2608 2640 2720  1440 1443 1448 1481
+hsync -vsync

% xrandr --output HDMI1 --mode 2560x1440