target/sparc: Fix FMUL8x16

target/sparc: Fix FMUL8x16

This instruction has f32 as source1, which alters the
decoding of the register number, which means we've been
passing the wrong data for odd register numbers.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20240502165528.244004-4-richard.henderson@linaro.org>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
(cherry picked from commit 9157dccc7e71f7c94581c38f38acbef9a21bbe9a)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>