libkrunfw: fix build failure when cross compiling to aarch64-linux (#526447)

pkgs/by-name/li/libkrunfw/package.nix

@@ -10,6 +10,7 @@
   perl,
   elfutils,
   python3,
+  buildPackages,
   variant ? null,
 }:
 
@@ -57,6 +58,7 @@ stdenv.mkDerivation (finalAttrs: {
 
   makeFlags = [
     "PREFIX=${placeholder "out"}"
+    "STRIP=${stdenv.cc.targetPrefix}strip"
   ]
   ++ lib.optionals (variant == "sev") [
     "SEV=1"
@@ -65,9 +67,14 @@ stdenv.mkDerivation (finalAttrs: {
     "TDX=1"
   ];
 
+  depsBuildBuild = [
+    elfutils
+    buildPackages.stdenv.cc
+  ];
+
   # Fixes https://github.com/containers/libkrunfw/issues/55
   env = lib.optionalAttrs stdenv.targetPlatform.isAarch64 {
-    NIX_CFLAGS_COMPILE = "-march=armv8-a+crypto";
+    NIX_CFLAGS_COMPILE_FOR_TARGET = "-march=armv8-a+crypto";
   };
 
   enableParallelBuilding = true;