common: Move dram_init() declaration to common location

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/include/asm/u-boot-arm.h b/arch/arm/include/asm/u-boot-arm.h
index f97f3dd..414042d 100644
--- a/arch/arm/include/asm/u-boot-arm.h
+++ b/arch/arm/include/asm/u-boot-arm.h
@@ -36,7 +36,6 @@
 
 /* board/.../... */
 int	board_init(void);
-int	dram_init (void);
 void	dram_init_banksize (void);
 
 /* cpu/.../interrupt.c */
diff --git a/arch/nds32/include/asm/u-boot-nds32.h b/arch/nds32/include/asm/u-boot-nds32.h
index b079086..dee5f43 100644
--- a/arch/nds32/include/asm/u-boot-nds32.h
+++ b/arch/nds32/include/asm/u-boot-nds32.h
@@ -22,7 +22,6 @@
 
 /* board/.../... */
 int	board_init(void);
-int	dram_init(void);
 
 /* cpu/.../interrupt.c */
 void	reset_timer_masked(void);
diff --git a/arch/sandbox/include/asm/u-boot-sandbox.h b/arch/sandbox/include/asm/u-boot-sandbox.h
index d2f1b65..770ab5c 100644
--- a/arch/sandbox/include/asm/u-boot-sandbox.h
+++ b/arch/sandbox/include/asm/u-boot-sandbox.h
@@ -17,7 +17,6 @@
 
 /* board/.../... */
 int board_init(void);
-int dram_init(void);
 
 /* start.c */
 int sandbox_early_getopt_check(void);
diff --git a/arch/x86/include/asm/u-boot-x86.h b/arch/x86/include/asm/u-boot-x86.h
index b98afa8..c24846b 100644
--- a/arch/x86/include/asm/u-boot-x86.h
+++ b/arch/x86/include/asm/u-boot-x86.h
@@ -26,15 +26,9 @@
 void timer_set_base(uint64_t base);
 int pcat_timer_init(void);
 
-/* Architecture specific DRAM init */
-int dram_init(void);
-
 /* cpu/.../interrupts.c */
 int cpu_init_interrupts(void);
 
-/* board/.../... */
-int dram_init(void);
-
 int cleanup_before_linux(void);
 int x86_cleanup_before_linux(void);
 void x86_enable_caches(void);
diff --git a/include/common.h b/include/common.h
index 97c8f79..9129454 100644
--- a/include/common.h
+++ b/include/common.h
@@ -183,6 +183,7 @@
 /*
  * Function Prototypes
  */
+int dram_init(void);
 
 void	hang		(void) __attribute__ ((noreturn));