ARC: Add optimized function to write core registers

Signed-off-by: Anton Kolesov <anton.kolesov@synopsys.com>
ARC: Use new functions to write to registers.

Signed-off-by: Anton Kolesov <anton.kolesov@synopsys.com>
ARC: non working aux registers

Signed-off-by: Anton Kolesov <anton.kolesov@synopsys.com>
ARC: Fix errors in JTAG

Signed-off-by: Anton Kolesov <anton.kolesov@synopsys.com>
ARC: Optimize core reg read operations

Signed-off-by: Anton Kolesov <anton.kolesov@synopsys.com>
ARC: Optimize AUX register readoperations

Signed-off-by: Anton Kolesov <anton.kolesov@synopsys.com>
ARC: Optimized memory reads.

Signed-off-by: Anton Kolesov <anton.kolesov@synopsys.com>