hwclock: remove cmos support

All PCs (even Alpha machines) have a Real Time Clock built into them.

Reference: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/rtc.txt#n35
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
hwclock: remove --badyear option

The Award BIOSes made between 4/26/94 and 5/31/95 is not expected to be
in use on systems using up to date util-linux package.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>