new real kind wp_init_grid used for icon grid initialization

src/mo_iconlib_kind.F90

@@ -22,6 +22,7 @@ MODULE mo_iconlib_kind
 
   PUBLIC :: wp !< Selected working precision
   PUBLIC :: vp !< Selected variable precision
+  PUBLIC :: wp_init_grid !< Selected precision for grid initialization
   PUBLIC :: dp !< 8 byte real (double precision)
   PUBLIC :: sp !< 4 byte real (single precision)
   PUBLIC :: i8 !< 8 byte integer
@@ -44,4 +45,6 @@ MODULE mo_iconlib_kind
   INTEGER, PARAMETER :: vp = wp
 #endif
 
+  INTEGER, PARAMETER :: wp_init_grid = dp
+
 END MODULE mo_iconlib_kind