support/dependencies/dependencies.sh: require open perl package for libxcrypt

Fixes:
http://autobuild.buildroot.net/results/16c/16cba783be11cc5024f9c56bb0a7abb0acf13ef8/

The configure script of libxcrypt needs the open perl module on the host:

Can't locate open.pm in @INC (you may need to install the open module) (@INC
contains: /home/buildroot/autobuild/instance-2/output-1/host/lib/perl
/usr/local/lib64/perl5/5.36 /usr/local/share/perl5/5.36
/usr/lib64/perl5/vendor_perl /usr/share/perl5/vendor_perl /usr/lib64/perl5
/usr/share/perl5) at ./build-aux/scripts/expand-selected-hashes line 20.

So add a check for it in dependencies.sh similar to how it is done for mpv.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit 4cdd99190e89d538c25a8fc701372775fbde3b97)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

support/dependencies/dependencies.sh

@@ -280,6 +280,10 @@ required_perl_modules="$required_perl_modules ExtUtils::MakeMaker" # Used by hos
 required_perl_modules="$required_perl_modules Thread::Queue" # Used by host-automake
 required_perl_modules="$required_perl_modules FindBin" # Used by (host-)libopenssl
 
+if grep -q ^BR2_PACKAGE_LIBXCRYPT=y $BR2_CONFIG ; then
+    required_perl_modules="$required_perl_modules open"
+fi
+
 if grep -q ^BR2_PACKAGE_MPV=y $BR2_CONFIG ; then
     required_perl_modules="$required_perl_modules Math::BigInt"
     required_perl_modules="$required_perl_modules Math::BigRat"