arch-power: Define more special purpose registers, mtspr,mfspr instructions

arch-power: Define more special purpose registers, mtspr,mfspr instructions

This patch defines more special purpose registers taking their count
to 49.

This also defines the mtspr and mfspr instructions to move the
contents to and from the these special purpose registers.

[ego@linux.vnet.ibm.com: Fixed conflicts in
	src/arch/power/isa/decoder.isa,
	src/arch/power/isa/operands.isa,
	src/arch/power/registers.hh]

[kajoljain797@gmail.com: Fixed rfid, hrfid, mtmsr, mtmsrd instructions]

NOTE: Perhaps can be folded into the previous patch which introduces
CR, MSR, PTCR, etc.

Change-Id: I4dd6ba8c710c4c522fadc685b60fb039dfd0a743

Signed-off-by: Phanikiran Harithas <phanikiran.harithas@gmail.com>
Signed-off-by:  Venkatnarayan Kulkarni <venkatnarayankulkarni@gmail.com>
Signed-off-by: Kajol Jain <kajoljain797@gmail.com>