package/php: fix gd extension dependencies and options

Due to migration to pkg-config in php 7.4, the detection of
library dependencies has been changed.

source from php.net:
--with-gd becomes --enable-gd
--with-png-dir has been removed. libpng is required.
--with-zlib-dir has been removed. zlib is required.
--with-freetype-dir becomes --with-freetype
--with-jpeg-dir becomes --with-jpeg

Signed-off-by: Louis Aussedat <aussedat.louis@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit 31c5fd8f4b1ee26881ac37e55b0967bed0c6ebd2)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/php/Config.ext

@@ -256,6 +256,7 @@ config BR2_PACKAGE_PHP_EXT_GD
 	select BR2_PACKAGE_FREETYPE
 	select BR2_PACKAGE_JPEG
 	select BR2_PACKAGE_LIBPNG
+	select BR2_PACKAGE_ZLIB
 	help
 	  GD support
 

package/php/php.mk

@@ -327,12 +327,10 @@ endif
 
 ifeq ($(BR2_PACKAGE_PHP_EXT_GD),y)
 PHP_CONF_OPTS += \
-	--with-gd \
-	--with-jpeg-dir=$(STAGING_DIR)/usr \
-	--with-png-dir=$(STAGING_DIR)/usr \
-	--with-zlib-dir=$(STAGING_DIR)/usr \
-	--with-freetype-dir=$(STAGING_DIR)/usr
-PHP_DEPENDENCIES += jpeg libpng freetype
+	--enable-gd \
+	--with-jpeg \
+	--with-freetype
+PHP_DEPENDENCIES += jpeg libpng freetype zlib
 endif
 
 ifeq ($(BR2_PACKAGE_PHP_SAPI_FPM),y)