[Buildroot] [git commit branch/2022.05.x] Revert "configs/olimex_a20_olinuxino_lime: use NEON+VFPv4 as FPU strategy"

[Peter Korsgaard]

commit: https://git.buildroot.net/buildroot/commit/?id=c50df50138874aafc0ecd8104dc0aa69ee14b56e
branch: https://git.buildroot.net/buildroot/commit/?id=refs/heads/2022.05.x

The gcc man page states that specifying Neon as part of the fpu setting
has no effect, unless the -funsafe-math-optimizations is also specified,
because Neon is not compliant with IEEE 754:
```
    If the selected floating-point hardware includes the NEON extension
    (e.g. -mfpu=neon), note that floating-point operations are not
    generated by GCC's auto-vectorization pass unless
    -funsafe-math-optimizations is also specified. This is because NEON
    hardware does not fully implement the IEEE 754 standard for
    floating-point arithmetic (in particular denormal values are treated
    as zero), so the use of NEON instructions may lead to a loss of
    precision.
```

-funsafe-math-optimizations must be explictly specified per package to
really use NEON as FPU, but it's something that is left to the user as
well as setting BR2_ARM_FPU_NEON_VFPV4. This way the default
BR2_ARM_FPU_VFPV4D16 is used as previously. So let's revert the
offending patch.

This reverts commit 115ee0521430d89db8be1a79457b0721ceafc484.

Signed-off-by: Giulio Benetti <giulio.benetti at benettiengineering.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998 at free.fr>
(cherry picked from commit d5c1e67d3adf4d5c32e94ad7eac7a940fb17f9f0)
Signed-off-by: Peter Korsgaard <peter at korsgaard.com>
---
 configs/olimex_a20_olinuxino_lime_defconfig | 1 -
 1 file changed, 1 deletion(-)

diff --git a/configs/olimex_a20_olinuxino_lime_defconfig b/configs/olimex_a20_olinuxino_lime_defconfig
index e24857e0c1..8403566a67 100644
--- a/configs/olimex_a20_olinuxino_lime_defconfig
+++ b/configs/olimex_a20_olinuxino_lime_defconfig
@@ -2,7 +2,6 @@
 BR2_arm=y
 BR2_cortex_a7=y
 BR2_ARM_EABIHF=y
-BR2_ARM_FPU_NEON_VFPV4=y
 
 # Linux headers same as kernel, a 5.15 LTS series
 BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_5_15=y