spl: Add function prototype for spl_mmc_get_uboot_raw_sector

We did not add a prototype for spl_mmc_get_uboot_raw_sector to
include/spl.h before, so add and document one now. Correct the incorrect
prototype in board/advantech/imx8mp_rsb3720a1/imx8mp_rsb3720a1.c and
ensure that we have spl.h where we define a non-weak
spl_mmc_get_uboot_raw_sector as well.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/mach-imx/image-container.c b/arch/arm/mach-imx/image-container.c
index 06ee608..5b059a6 100644
--- a/arch/arm/mach-imx/image-container.c
+++ b/arch/arm/mach-imx/image-container.c
@@ -10,6 +10,7 @@
 #include <asm/io.h>
 #include <mmc.h>
 #include <spi_flash.h>
+#include <spl.h>
 #include <nand.h>
 #include <asm/mach-imx/image.h>
 #include <asm/arch/sys_proto.h>
diff --git a/board/advantech/imx8mp_rsb3720a1/imx8mp_rsb3720a1.c b/board/advantech/imx8mp_rsb3720a1/imx8mp_rsb3720a1.c
index 34109c6..09e63e0 100644
--- a/board/advantech/imx8mp_rsb3720a1/imx8mp_rsb3720a1.c
+++ b/board/advantech/imx8mp_rsb3720a1/imx8mp_rsb3720a1.c
@@ -208,7 +208,8 @@
 
 #ifdef CONFIG_SPL_MMC
 #define UBOOT_RAW_SECTOR_OFFSET 0x40
-unsigned long spl_mmc_get_uboot_raw_sector(struct mmc *mmc)
+unsigned long spl_mmc_get_uboot_raw_sector(struct mmc *mmc,
+					   unsigned long raw_sector)
 {
 	u32 boot_dev = spl_boot_device();
 
diff --git a/include/spl.h b/include/spl.h
index bad12fb..7e0f5ac 100644
--- a/include/spl.h
+++ b/include/spl.h
@@ -467,6 +467,19 @@
 void spl_set_bd(void);
 
 /**
+ * spl_mmc_get_uboot_raw_sector() - Provide raw sector of the start of U-Boot
+ *
+ * This is a weak function which by default will provide the raw sector that is
+ * where the start of the U-Boot image has been written to.
+ *
+ * @mmc: struct mmc that describes the devie where U-Boot resides
+ * @raw_sect: The raw sector number where U-Boot is by default.
+ * Return: The raw sector location that U-Boot resides at
+ */
+unsigned long spl_mmc_get_uboot_raw_sector(struct mmc *mmc,
+					   unsigned long raw_sect);
+
+/**
  * spl_set_header_raw_uboot() - Set up a standard SPL image structure
  *
  * This sets up the given spl_image which the standard values obtained from