[IA64] remove unused PAL_CALL_IC_OFF

Linux maps PAL instructions with an ITR, but uses a DTC for PAL data.
Section 11.10.2.1.3, "Making PAL Procedures Calls in Physical or Virtual
Mode," of the SDM (rev 2.2), says we must therefore make all PAL calls
with PSR.ic = 1 so that Linux can handle any TLB faults.

PAL_CALL_IC_OFF is currently unused, and as long as we use the ITR + DTC
strategy, we can't use it.  So remove it.  I also removed the code in
ia64_pal_call_static() that conditionally cleared PSR.ic.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>