MIPS: R6: emulation of MIPS R2 removed instructions.

MIPS: R6: emulation of MIPS R2 removed instructions.

MIPS R6 architecture has deleted some MIPS R2 instructions.
This patch does emulation of that instructions in kernel.

Squashed:
	5465a192ac70 R6 emulation of MIPS R2: restore MIPS32 R6 build
	1cdef69e7305 MIPS: R6: R2 emulation optimisation
	ece19295b50e MIPS: R6: FRE mode support for R2 emulation
	666439e519f1 MIPS: Build: bind R2 and incompatible FPU emulation together
	3be8d0f9a1d8 MIPS: R6: R2 emulation bugfixes in negative signal return
	aefc61dfb88a MIPS: R6: R2 emulation bugfix of address in process_fpemu_return
	8b7d02f5263b MIPS: R6: R2 emulation bugfix of EVA by LLE/SCE opcodes
	7f403f401c6d MIPS: R6 emulation of R2 bugfix of LWR instruction
	07c2979e66b3 MIPS: bugfix of FR0/1 setup failure processing

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>