instructions: increase number of GPR's to 16.

This makes it possible to have a dedicated frame pointer and enough
registers to be useful for a compiler without lots of stack local
storage.
sim: increase number of GPR's to 16.
debugger: increase number of GPR's to 16.
bootrom: fixup move to 16 GPR's.

We now only have 13 bits for load/store immediates so we use orlo to a
temporary register.
tests: fixup or/orlo usage.

or uses a 13 bit immediate but we really need 16 bits, use orlo.
tools/gtkwave: correct MOV ALU opcode definition.
rtl: convert to v2 register set.

The version 2 register set has 16 general purpose registers with 3
registers designated as frame pointer, link register and stack pointer.
binutils: update to latest revision.