Allow non-sequential core registers in one JTAG call

Signed-off-by: Anton Kolesov <anton.kolesov@synopsys.com>
Rename core registers as well

Signed-off-by: Anton Kolesov <anton.kolesov@synopsys.com>
Finish save/restore context functions

Signed-off-by: Anton Kolesov <anton.kolesov@synopsys.com>
Remove tons of commented code

Signed-off-by: Anton Kolesov <anton.kolesov@synopsys.com>
ARC: Remove print core/aux regs commands

OpenOCD already has command "reg" to read/write registers. It doesn't
differ core and aux registers though. It also print !exist registers,
but I think this one is a bug. Also no other arch seems to implement
command like this.

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

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