Wip - split target setup and target examination

src/target/arm720t.c

src/target/arm7tdmi.c

src/target/arm7tdmi.h

src/target/arm920t.c

src/target/arm926ejs.c

src/target/arm966e.c

src/target/arm9tdmi.c

src/target/arm9tdmi.h

src/target/feroceon.c

src/target/target.c