Juan 25/07/2023:ZSOLVER/mode_splittingz_ll.f90,for MultiGrid 2^N , first split Y axis then X axis

src/ZSOLVER/SURCOUCHE/mode_splittingz_ll.f90

@@ -245,8 +245,8 @@ CONTAINS
     !
     CALL DEF_SPLITTING2(JX_DOMAINS,JY_DOMAINS,NIMAX_TMP_ll,NJMAX_TMP_ll,NPROC,LPREM)
     !
-    P1 = JX_DOMAINS
-    IF (DIMZ .NE. 3 )    P1 = MIN(DIMZ,JX_DOMAINS)
+    P1 = JY_DOMAINS
+    IF (DIMZ .NE. 3 )    P1 = MIN(DIMZ,JY_DOMAINS)
     IF (NZ_PROC .GT. 0 ) P1 = NZ_PROC
     P2 = NPROC / P1
     !JUAN PATCH NESTING DIFFERENT SHAPE