zip: remove host build

This is conflicting with tools/zip where the HostBuild is specified.
This should allow the zip package to show up.

Several cleanups were also performed for consistency between packages.

Added PKG_BUILD_PARALLEL:=1 for faster compilation.

Remove PKG_CHECK_FORMAT_SECURITY. Patched the issue instead.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

utils/zip/patches/020-format.patch

@@ -0,0 +1,22 @@
+--- a/zip.c
++++ b/zip.c
+@@ -1028,8 +1028,7 @@ local void help_extended()
+ 
+   for (i = 0; i < sizeof(text)/sizeof(char *); i++)
+   {
+-    printf(text[i]);
+-    putchar('\n');
++    puts(text[i]);
+   }
+ #ifdef DOS
+   check_for_windows("Zip");
+@@ -1225,8 +1224,7 @@ local void version_info()
+             CR_MAJORVER, CR_MINORVER, CR_BETA_VER, CR_VERSION_DATE);
+   for (i = 0; i < sizeof(cryptnote)/sizeof(char *); i++)
+   {
+-    printf(cryptnote[i]);
+-    putchar('\n');
++    puts(cryptnote[i]);
+   }
+   ++i;  /* crypt support means there IS at least one compilation option */
+ #endif /* CRYPT */