[ARM] pxa: move common MFP handling code into plat-pxa

arch/arm/mach-pxa/include/mach/mfp-pxa25x.h

arch/arm/mach-pxa/include/mach/mfp-pxa27x.h

arch/arm/mach-pxa/include/mach/mfp-pxa2xx.h

arch/arm/mach-pxa/include/mach/mfp-pxa300.h

arch/arm/mach-pxa/include/mach/mfp-pxa320.h

arch/arm/mach-pxa/include/mach/mfp-pxa3xx.h

arch/arm/mach-pxa/include/mach/mfp-pxa930.h

arch/arm/mach-pxa/mfp-pxa3xx.c

arch/arm/mach-pxa/pxa300.c

arch/arm/mach-pxa/pxa320.c

arch/arm/mach-pxa/pxa930.c

arch/arm/plat-pxa/Makefile

arch/arm/plat-pxa/include/plat/mfp.h

arch/arm/plat-pxa/mfp.c