[oe] [meta-oe][ 13/32] fftw: Add -D_GNU_SOURCE to CFLAGS

[Khem Raj]

Helps fix build on musl

Signed-off-by: Khem Raj <raj.khem at gmail.com>
---
 meta-oe/recipes-support/fftw/fftw_3.3.6.bb | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/meta-oe/recipes-support/fftw/fftw_3.3.6.bb b/meta-oe/recipes-support/fftw/fftw_3.3.6.bb
index 559985169..ed14e1658 100644
--- a/meta-oe/recipes-support/fftw/fftw_3.3.6.bb
+++ b/meta-oe/recipes-support/fftw/fftw_3.3.6.bb
@@ -19,6 +19,8 @@ PROVIDES = "fftwl fftwf"
 
 EXTRA_OECONF = "--disable-fortran --enable-shared --enable-threads"
 
+CFLAGS += "-D_GNU_SOURCE"
+
 FFTW_NEON = "${@bb.utils.contains('TUNE_FEATURES', 'neon', '--enable-neon', '', d)}"
 FFTW_NEON_class-native = ""
 
-- 
2.12.2