php: security bump to version 5.6.22

Fixes:
Core: Integer Overflow in php_html_entities
Core: Integer underflow / arbitrary null write in fread/gzread
GD: imagescale out-of-bounds read
Intl: get_icu_value_internal out-of-bounds read

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/php/php.hash

@@ -1,2 +1,2 @@
 # From http://php.net/downloads.php
-sha256	566ff1a486cb0485ed477a91ea292423f77a58671270ff73b74e67e3ce7084f9	php-5.6.21.tar.xz
+sha256	c96980d7de1d66c821a4ee5809df0076f925b2fe0b8c362d234d92f2f0a178e2	php-5.6.22.tar.xz

package/php/php.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-PHP_VERSION = 5.6.21
+PHP_VERSION = 5.6.22
 PHP_SITE = http://www.php.net/distributions
 PHP_SOURCE = php-$(PHP_VERSION).tar.xz
 PHP_INSTALL_STAGING = YES