hwclock: move command-line options to control structure

hwclock: move command-line options to control structure

The control structure is read-only everywhere else but in main().  Almost
all changes are about how variables are referred, with one exception.  Calls
to read_adjtime() from manipulate_clock() and compare_clock() are moved to
main().  This way it is possible to keep variable that tells if hwclock is
using UTC-0 be part of control structure.

Changes within #ifdef __alpha__ segments were tested by flipping the
preprocessor directivive otherway around and getting good compilaton all the
way to the point where linking on none-alpha system failed.

Reviewed-by: J William Piggott <elseifthen@gmx.com>
Signed-off-by: Sami Kerola <kerolasa@iki.fi>