Add patch for powerpc

build/pkgs/openblas/patches/powerpc.patch

@@ -0,0 +1,21 @@
+commit 41407acc19cd3ca2ee4ab965ed5e19d7776e669e
+Author: Sébastien Villemot <sebastien@debian.org>
+Date:   Mon Nov 9 18:36:04 2015 +0100
+
+    Fix detection of POWER architecture in c_check.
+
+    This is necessary to avoid the false detection of a cross-compiling
+    environment.
+
+diff --git a/c_check b/c_check
+index d694e74..bcf4c2c 100644
+--- a/c_check
++++ b/c_check
+@@ -6,6 +6,7 @@ $hostarch = `uname -m | sed -e s/i.86/x86/`;chop($hostarch);
+ $hostarch = "x86_64" if ($hostarch eq "amd64");
+ $hostarch = "arm" if ($hostarch =~ /^arm.*/);
+ $hostarch = "arm64" if ($hostarch eq "aarch64");
++$hostarch = "power" if ($hostarch =~ /^(powerpc|ppc).*/);
+
+ $binary = $ENV{"BINARY"};
+