Added support in the hwc to provide refresh timestamps to the surface flinger.

Added support in the hwc to provide refresh timestamps to the surface flinger.

It is done using the same fake mechanism as SF uses. This is prefered until the refresh time stamps will be provides.

v4 (topi):
  - switched upper-case style to underscores
  - remove code parts that should not be part of this patch but future patch
  - update SEC_TO_NANOSEC defined directive and use it in all code.
  - wrong comments style fix.
  - one-line bodies without the brackets,pure whitespace change

v5 (topi/tapani):
  - Indentations fix.
  - compiler warning separate patch
  - include explanation here for 'enabled' and 'disp'
  - added VSYNC missed warning.
  - typo fix.

v6(topi/tapani):
  - 'vsync missed!' message fixed.
  - indentation and newline fixed.

Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
Change-Id: I927e62b5c8c53db859bd194b75f1b92028ea0d85
Signed-off-by: Marius Predut <marius-ionut.predut@intel.com>