Gradle, native: Fix building platform libraries for MIPS

The sysroot for linux_mips doesn't contain one of platform
libs available for Linux (zlib). So we need to put def-files
to the K/N distribution on a per-target basis instead of putting
a single set of def-files for all targets of the same OS.

Corresponding change in the K/N repository:
https://github.com/JetBrains/kotlin-native/pull/4023

This patch take this change into account at the Gradle plugin side.

native/utils/src/org/jetbrains/kotlin/konan/target/Distribution.kt

@@ -91,7 +91,7 @@ class Distribution(
 
     fun runtime(target: KonanTarget) = runtimeFileOverride ?: "$stdlibDefaultComponent/targets/${target.visibleName}/native/runtime.bc"
 
-    fun platformDefs(family: Family) = "$konanHome/konan/platformDef/${family.visibleName}"
+    fun platformDefs(target: KonanTarget) = "$konanHome/konan/platformDef/${target.visibleName}"
 
     fun platformLibs(target: KonanTarget) = "$klib/platform/${target.visibleName}"