drm/ast: Move struct ast_dramstruct to ast_post.h

Declare struct ast_dramstruct in ast_post.h and remove its original
header file.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20250706162816.211552-7-tzimmermann@suse.de

Author: tdz

drivers/gpu/drm/ast/ast_2000.c

@@ -28,8 +28,8 @@
 
 #include <linux/delay.h>
 
-#include "ast_dram_tables.h"
 #include "ast_drv.h"
+#include "ast_post.h"
 
 /*
  * POST

drivers/gpu/drm/ast/ast_2100.c

@@ -28,8 +28,8 @@
 
 #include <linux/delay.h>
 
-#include "ast_dram_tables.h"
 #include "ast_drv.h"
+#include "ast_post.h"
 
 /*
  * POST

drivers/gpu/drm/ast/ast_dram_tables.h

@@ -7,6 +7,12 @@
 
 struct ast_device;
 
+/* DRAM timing tables */
+struct ast_dramstruct {
+	u16 index;
+	u32 data;
+};
+
 u32 __ast_mindwm(void __iomem *regs, u32 r);
 void __ast_moutdwm(void __iomem *regs, u32 r, u32 v);