change all other clock references to use nanosecond resolution accessors

This was done with:

    sed -i 's/qemu_get_clock\>/qemu_get_clock_ns/' \
        $(git grep -l 'qemu_get_clock\>' )
    sed -i 's/qemu_new_timer\>/qemu_new_timer_ns/' \
        $(git grep -l 'qemu_new_timer\>' )

after checking that get_clock and new_timer never occur twice
on the same line.  There were no missed occurrences; however, even
if there had been, they would have been caught by the compiler.

There was exactly one false positive in qemu_run_timers:

     -    current_time = qemu_get_clock (clock);
     +    current_time = qemu_get_clock_ns (clock);

which is of course not in this patch.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/hw/vga.c b/hw/vga.c
index 3ef85fb..124295a 100644
--- a/hw/vga.c
+++ b/hw/vga.c
@@ -260,7 +260,7 @@
         int cur_line, cur_line_char, cur_char;
         int64_t cur_tick;
 
-        cur_tick = qemu_get_clock(vm_clock);
+        cur_tick = qemu_get_clock_ns(vm_clock);
 
         cur_char = (cur_tick / r->ticks_per_char) % r->total_chars;
         cur_line = cur_char / r->htotal;