Better fix for TAPs violating the JTAG spec for IR-Capture.

Instead of just assuming all IDCODE-deprived TAPs violate the
JTAG spec (they don't!), just require TAPs with such problems
to be declared with proper ircapture/irmask values.  Example,
with mask and value of zero.


git-svn-id: svn://svn.berlios.de/openocd/trunk@2823 b42882b7-edfa-0310-969c-e2dbd0fdcd60