target/arm: Move softfloat specific FPCR/FPSR handling to tcg/

target/arm: Move softfloat specific FPCR/FPSR handling to tcg/

The softfloat (i.e. TCG) specific handling for the FPCR
and FPSR is abstracted behind five functions:
 arm_set_default_fp_behaviours
 arm_set_ah_fp_behaviours
 vfp_get_fpsr_from_host
 vfp_clear_float_status_exc_flags
 vfp_set_fpsr_to_host

Currently we rely on the first two calling softfloat functions that
work even in a KVM-only compile because they're defined as inline in
the softfloat header file, and we provide stub versions of the last
three in arm/vfp_helper.c if CONFIG_TCG isn't defined.

Move the softfloat-specific versions of these functions to
tcg/vfp_helper.c, and provide the non-TCG stub versions in
tcg-stubs.c.

This lets us drop the softfloat header include and the last
set of CONFIG_TCG ifdefs from arm/vfp_helper.c.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20250221190957.811948-4-peter.maydell@linaro.org