package/php: remove CFLAGS for OPcache extension

Buildroot commit aedf131da6 bumped the
package to 8.5.0 which made opcache a mandatory dependency but kept the
CFLAGS added in 2015 with buildroot commit
e054764917.

As it turns out we need to remove the CFLAGS to fix the build with the
bootlin-aarch64-glibc-old defconfig as detected by the Gitlab pipelines:

ext/opcache/shared_alloc_posix.o: In function `create_segments':
shared_alloc_posix.c:(.text+0xcc): undefined reference to `shm_open'
shared_alloc_posix.c:(.text+0x11c): undefined reference to `shm_unlink'
shared_alloc_posix.c:(.text+0x19c): undefined reference to `shm_unlink'
shared_alloc_posix.c:(.text+0x1b8): undefined reference to `shm_unlink'

as they seem to disturb the detection of librt.

It is unclear which upstream commits added since 2015 fixed the original
problem so a backport to LTS branches is not advised.

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

package/php/php.mk

@@ -78,15 +78,6 @@ PHP_CONFIG_SCRIPTS = php-config
 PHP_CFLAGS = $(TARGET_CFLAGS)
 PHP_CXXFLAGS = $(TARGET_CXXFLAGS)
 
-# The OPcache extension isn't cross-compile friendly
-# Throw some defines here to avoid patching heavily
-PHP_CFLAGS += \
-	-DHAVE_SHM_IPC \
-	-DHAVE_SHM_MMAP_ANON \
-	-DHAVE_SHM_MMAP_ZERO \
-	-DHAVE_SHM_MMAP_POSIX \
-	-DHAVE_SHM_MMAP_FILE
-
 # We need to force dl "detection"
 ifeq ($(BR2_STATIC_LIBS),)
 PHP_CONF_ENV += ac_cv_func_dlopen=yes ac_cv_lib_dl_dlopen=yes