package/perl-extutils-pkgconfig: set PATH to BR_PATH

Set PATH to BR_PATH to allow perl-extutils-pkgconfig to find pkg-config
binary

Fixes:
 - http://autobuild.buildroot.org/results/d87787fbf2a8cb9bbaa3b59d1e8004ad1459536a

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/perl-extutils-pkgconfig/perl-extutils-pkgconfig.mk

@@ -13,4 +13,6 @@ PERL_EXTUTILS_PKGCONFIG_DISTNAME = ExtUtils-PkgConfig
 
 HOST_PERL_EXTUTILS_PKGCONFIG_DEPENDENCIES = host-pkgconf
 
+HOST_PERL_EXTUTILS_PKGCONFIG_CONF_ENV = PATH=$(BR_PATH)
+
 $(eval $(host-perl-package))