Patched FMS2-branch to work with FMS1

- Added missing #ifdef to avoid compilation errors when using an older FMS
- Changed "use_deprecated_io" to "USE_FMS2_IO"
  - The word "deprecated" has a limited lifetime (consider what to use when
    FMS2 is replaced).
  - Backwards compatibility requires that no macros are needed to use
    FMS1. That is, the new stuff can use -DUSE_FMS2_IO but the old stuff
    should not be require any changes.

src/icebergs_fms2io.F90

@@ -1,5 +1,6 @@
 !> Handles reading/writing of restart files and trajectory-based diagnostic files
 module ice_bergs_fms2io
+#ifdef USE_FMS2_IO
 
 ! This file is part of NOAA-GFDL/icebergs. See LICENSE.md for the license.
 
@@ -2765,4 +2766,5 @@ subroutine register_axis_wrapper(fileobj)
    enddo
 end subroutine register_axis_wrapper
 
+#endif
 end module

src/icebergs_fmsio.F90

@@ -1,6 +1,7 @@
 !> Handles reading/writing of restart files and trajectory-based diagnostic files
 module ice_bergs_fmsio
-#ifdef use_depreciated_io
+#ifndef USE_FMS2_IO
+
 ! This file is part of NOAA-GFDL/icebergs. See LICENSE.md for the license.
 
 use mpp_domains_mod, only: domain2D
@@ -2492,5 +2493,6 @@ logical function find_restart_file(filename, actual_file, multiPErestart, tile_i
   multiPErestart=.false.
 
 end function find_restart_file
+
 #endif
 end module

src/icebergs_io.F90

@@ -2,7 +2,7 @@
 module ice_bergs_io
 ! This file is part of NOAA-GFDL/icebergs. See LICENSE.md for the license.
 
-#ifdef use_depreciated_io
+#ifndef USE_FMS2_IO
   use ice_bergs_fmsio
 #else
   use ice_bergs_fms2io