netcdf: Add portablexdr as a dependency

Fixes #545.

Signed-off-by: Timothy Gu <timothygu99@gmail.com>

src/netcdf.mk

@@ -8,7 +8,7 @@ $(PKG)_CHECKSUM := 246e4963e66e1c175563cc9a714e9da0a19b8b07
 $(PKG)_SUBDIR   := $(PKG)-$($(PKG)_VERSION)
 $(PKG)_FILE     := $(PKG)-$($(PKG)_VERSION).tar.gz
 $(PKG)_URL      := http://www.unidata.ucar.edu/downloads/netcdf/ftp/$($(PKG)_FILE)
-$(PKG)_DEPS     := gcc curl zlib hdf4 hdf5
+$(PKG)_DEPS     := gcc curl hdf4 hdf5 portablexdr zlib
 
 define $(PKG)_UPDATE
     $(WGET) -q -O- 'http://www.unidata.ucar.edu/downloads/netcdf/index.jsp' | \