Revert "php: fix build for xtensa"

This reverts commit 410c3cf7ebe69016e73bbe63d1ba4b0a251b5c9a.
Now that -mtext-section-literals is specified in the xtensa ABI this fix
is no longer needed.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/php/php.mk

@@ -45,10 +45,6 @@ ifneq ($(BR2_INET_IPV6),y)
 endif
 endif
 
-ifeq ($(BR2_xtensa),y)
-PHP_CFLAGS += -mtext-section-literals
-endif
-
 PHP_CONF_OPT += $(if $(BR2_PACKAGE_PHP_CLI),,--disable-cli)
 PHP_CONF_OPT += $(if $(BR2_PACKAGE_PHP_CGI),,--disable-cgi)