REFAC: remove hdf5 patch for gdal and set HDF5_H5_IS_DLL variable instead (gdal 3.1.0)

SuperBuild/patches/GDAL/gdal-4-fixhdf5-win.diff

---- gdal-2.4.1_orig/frmts/hdf5/makefile.vc	2019-03-15 13:30:02.000000000 +0100
-+++ gdal-2.4.1/frmts/hdf5/makefile.vc	2019-04-05 17:43:22.356322797 +0200
-@@ -7,7 +7,7 @@
- 
- PLUGIN_DLL 	=	gdal_HDF5.dll
- 
--EXTRAFLAGS 	= 	-I$(HDF5_DIR)\include -DWIN32 -D_HDF5USEDLL_ 
-+EXTRAFLAGS 	= 	-I$(HDF5_DIR)\include -DWIN32 -DH5_BUILT_AS_DYNAMIC_LIB 
- 
- !IF "$(HDF5_PLUGIN)" == "YES"
- EXTRAFLAGS = $(EXTRAFLAGS) -DHDF5_PLUGIN

SuperBuild/patches/GDAL/nmake_gdal_extra.opt.in

@@ -109,6 +109,10 @@ NETCDF_INC_DIR = @SB_INSTALL_PREFIX_NATIVE@\include
 NETCDF_HAS_NC4 = YES
 NETCDF_HAS_HDF4 = YES
 
+# Needed to define H5_BUILT_AS_DYNAMIC_LIB for windows compilation 
+# scenarios where it is not exported on the target (non-CMake builds)
+HDF5_H5_IS_DLL = YES
+
 # Binding list. One or several in the following list
 # csharp, java, python
 BINDINGS=python