added PMBUILDs for dropbear linux zlib and fix for busybox uclibc

scripts/zlib/PMBUILD

@@ -0,0 +1,29 @@
+pkgname=zlib
+pkgver=1.3.1
+pkgrel=1
+source="https://www.zlib.net/zlib-1.3.1.tar.gz"
+deps="uClibc-ng"
+
+export PATH=$PATH:/opt/toolchains/arm-buildroot-linux-uclibcgnueabihf/bin
+export CROSS_COMPILE=arm-buildroot-linux-uclibcgnueabihf
+export ARCH=arm
+
+configure() {
+    cd $srcdir
+    tar -xvf $pkgname-$pkgver.tar.gz
+    cd -
+    export srcdir=$srcdir/$pkgname-$pkgver
+    cd $srcdir
+    CC=${CROSS_COMPILE}-gcc ./configure --prefix=/usr --shared
+    cd -
+}
+
+build() {
+    make -C $srcdir -j$(nproc)
+}
+
+package() {
+    make -C $srcdir DESTDIR=$pkgdir install
+    ${CROSS_COMPILE}-strip --strip-unneeded $pkgdir/usr/lib/libz.so.${pkgver}
+    rm -rv $pkgdir/usr/{include,share} $pkgdir/usr/lib/pkgconfig $pkgdir/usr/lib/*.a
+}