Make the order of the header file includes consistent in backend modules.

Similar to commits 7e735035f2 and dddf4cdc33, this commit makes the order
of header file inclusion consistent for backend modules.

In the passing, removed a couple of duplicate inclusions.

Author: Vignesh C
Reviewed-by: Kuntal Ghosh and Amit Kapila
Discussion: https://postgr.es/m/CALDaNm2Sznv8RR6Ex-iJO6xAdsxgWhCoETkaYX=+9DW3q0QCfA@mail.gmail.com

src/backend/access/brin/brin_minmax.c

@@ -10,19 +10,18 @@
  */
 #include "postgres.h"
 
-#include "access/genam.h"
 #include "access/brin_internal.h"
 #include "access/brin_tuple.h"
+#include "access/genam.h"
 #include "access/stratnum.h"
-#include "catalog/pg_type.h"
 #include "catalog/pg_amop.h"
+#include "catalog/pg_type.h"
 #include "utils/builtins.h"
 #include "utils/datum.h"
 #include "utils/lsyscache.h"
 #include "utils/rel.h"
 #include "utils/syscache.h"
 
-
 typedef struct MinmaxOpaque
 {
 	Oid			cached_subtype;

src/backend/access/brin/brin_pageops.c

@@ -10,8 +10,8 @@
  */
 #include "postgres.h"
 
-#include "access/brin_pageops.h"
 #include "access/brin_page.h"
+#include "access/brin_pageops.h"
 #include "access/brin_revmap.h"
 #include "access/brin_xlog.h"
 #include "access/xloginsert.h"
@@ -22,7 +22,6 @@
 #include "storage/smgr.h"
 #include "utils/rel.h"
 
-
 /*
  * Maximum size of an entry in a BRIN_PAGETYPE_REGULAR page.  We can tolerate
  * a single item per page, unlike other index AMs.

src/backend/access/brin/brin_tuple.c

@@ -31,14 +31,13 @@
  */
 #include "postgres.h"
 
-#include "access/htup_details.h"
 #include "access/brin_tuple.h"
+#include "access/htup_details.h"
 #include "access/tupdesc.h"
 #include "access/tupmacs.h"
 #include "utils/datum.h"
 #include "utils/memutils.h"
 
-
 static inline void brin_deconstruct_tuple(BrinDesc *brdesc,
 										  char *tp, bits8 *nullbits, bool nulls,
 										  Datum *values, bool *allnulls, bool *hasnulls);

src/backend/access/brin/brin_validate.c

@@ -22,9 +22,8 @@
 #include "catalog/pg_opfamily.h"
 #include "catalog/pg_type.h"
 #include "utils/builtins.h"
-#include "utils/syscache.h"
 #include "utils/regproc.h"
-
+#include "utils/syscache.h"
 
 /*
  * Validator for a BRIN opclass.