spl: stm32f7: configure for xip booting

With xip booting configuration, we don't need to copy the next image
(U-Boot or linux xipimage) from flash to sdram area.

Flash memory organization is like this:
	spl-U-Boot:	u-boot-spl.bin 	: 0x0800_0000
	U-Boot :	u-boot-dtb.bin	: 0x0800_8000
	linux :		xipImage	: 0x0800_8000

It is also possible to have U-Boot binary & linux binaries configured at
different addresses of flash memory like U-Boot at 0x0800_8000 & linux
xipImage at 0x0800_4000. But in any case, spl-U-Boot needs to be compiled for
U-Boot as next binary with SPL_OS_BOOT option disabled.
By default, spl is configured to boot linux xipImage.

Signed-off-by: Vikas Manocha <vikas.manocha@st.com>

arch/arm/mach-stm32/Kconfig

@@ -26,6 +26,7 @@ config STM32F7
 	select SPL_RAM
 	select SPL_SERIAL_SUPPORT
 	select SPL_SYS_MALLOC_SIMPLE
+	select SPL_XIP_SUPPORT
 
 source "arch/arm/mach-stm32/stm32f4/Kconfig"
 source "arch/arm/mach-stm32/stm32f1/Kconfig"

board/st/stm32f746-disco/stm32f746-disco.c

@@ -117,7 +117,7 @@ void spl_board_init(void)
 }
 u32 spl_boot_device(void)
 {
-	return BOOT_DEVICE_NOR;
+	return BOOT_DEVICE_XIP;
 }
 
 #endif

include/configs/stm32f746-disco.h

@@ -12,17 +12,18 @@
 #define CONFIG_SYS_INIT_SP_ADDR		0x20050000
 
 #ifdef CONFIG_SUPPORT_SPL
-#define CONFIG_SYS_TEXT_BASE		0xC0000000
+#define CONFIG_SYS_TEXT_BASE		0x08008000
+#define CONFIG_SYS_LOAD_ADDR		0x08008000
 #else
 #define CONFIG_SYS_TEXT_BASE		CONFIG_SYS_FLASH_BASE
+#define CONFIG_SYS_LOAD_ADDR		0xC0400000
+#define CONFIG_LOADADDR			0xC0400000
 #endif
 
 /*
  * Configuration of the external SDRAM memory
  */
 #define CONFIG_NR_DRAM_BANKS		1
-#define CONFIG_SYS_LOAD_ADDR		0xC0400000
-#define CONFIG_LOADADDR			0xC0400000
 
 #define CONFIG_SYS_MAX_FLASH_SECT	8
 #define CONFIG_SYS_MAX_FLASH_BANKS	1
@@ -83,16 +84,13 @@
 #define CONFIG_SPL_TEXT_BASE		CONFIG_SYS_FLASH_BASE
 #define CONFIG_SYS_MONITOR_LEN		(512 * 1024)
 #define CONFIG_SYS_SPL_LEN		0x00008000
-#define CONFIG_SYS_UBOOT_START		0XC00003FD
+#define CONFIG_SYS_UBOOT_START		0x080083FD
 #define CONFIG_SYS_UBOOT_BASE		(CONFIG_SYS_FLASH_BASE + \
 					 CONFIG_SYS_SPL_LEN)
 
-#define CONFIG_SYS_OS_BASE		0x08040000
 /* DT blob (fdt) address */
-#define CONFIG_SYS_SPL_ARGS_ADDR        0xC0000100
 #define CONFIG_SYS_FDT_BASE		(CONFIG_SYS_FLASH_BASE + \
 					0x1C0000)
-#define CONFIG_SYS_FDT_SIZE		(20*1024)
 #endif
 /* For SPL ends */