[PATCH 1/2]support64: Add functions into types and target

[PATCH 1/2]support64: Add functions into types and target

Add functions into types.h, target.c, target.h to operate 64bits data.
Prepare for 64bits mips target.

Change-Id: I668a8a5ac12ba754ae310fa6e92cfc91af850b1c
Signed-off-by: Dongxue Zhang <elta.era@gmail.com>
Reviewed-on: http://openocd.zylin.com/1700
Tested-by: jenkins
Reviewed-by: Mathias Küster <kesmtp@freenet.de>
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>