tcg/ppc: Update vector support for v2.07 FP

tcg/ppc: Update vector support for v2.07 FP

These new instructions are conditional on MSR.FP when TX=0 and
MSR.VEC when TX=1.  Since we only care about the Altivec registers,
and force TX=1, we can consider these to be Altivec instructions.
Since Altivec is true for any use of vector types, we only need
test have_isa_2_07.

This includes moves to and from the integer registers.

Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>