package/ffmpeg: fix build on i386

Fixes build error:

/home/thomas/autobuild/instance-0/output-1/host/lib/gcc/i686-buildroot-linux-musl/15.3.0/../../../../i686-buildroot-linux-musl/bin/ld:
 libavutil/x86/tx_float.o: warning:
 relocation in read-only section `.text'
/home/thomas/autobuild/instance-0/output-1/host/lib/gcc/i686-buildroot-linux-musl/15.3.0/../../../../i686-buildroot-linux-musl/bin/ld:
 read-only segment has dynamic relocations
collect2: error: ld returned 1 exit status

For details see:
https://bugzilla.redhat.com/show_bug.cgi?id=2428281
786464f239

Fixes:
https://autobuild.buildroot.net/results/c3a/c3ae9a6e6f6c4060feaa1d62dbc2b08da2437f38/

The oldest build error of this kind dates back to 2024:
https://autobuild.buildroot.net/results/e66/e665577347857b548f34f9b4fc86f2c573f27282/
so a backport to LTS branches should be considered.

Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
Signed-off-by: Julien Olivain <ju.o@free.fr>

package/ffmpeg/ffmpeg.mk

@@ -584,6 +584,7 @@ FFMPEG_CONF_OPTS += --cpu="$(GCC_TARGET_ARCH)"
 endif
 
 FFMPEG_CFLAGS = $(TARGET_CFLAGS)
+FFMPEG_LDFLAGS = $(TARGET_LDFLAGS)
 
 ifeq ($(BR2_TOOLCHAIN_HAS_GCC_BUG_85180),y)
 FFMPEG_CONF_OPTS += --disable-optimizations
@@ -599,7 +600,11 @@ ifeq ($(BR2_ARM_INSTRUCTIONS_THUMB),y)
 FFMPEG_CFLAGS += -marm
 endif
 
-FFMPEG_CONF_ENV += CFLAGS="$(FFMPEG_CFLAGS)"
+ifeq ($(BR2_i386),y)
+FFMPEG_LDFLAGS += -Wl,-z,notext
+endif
+
+FFMPEG_CONF_ENV += CFLAGS="$(FFMPEG_CFLAGS)" LDFLAGS="$(FFMPEG_LDFLAGS)"
 FFMPEG_CONF_OPTS += $(call qstrip,$(BR2_PACKAGE_FFMPEG_EXTRACONF))
 
 # Override FFMPEG_CONFIGURE_CMDS: FFmpeg does not support --target and others