spl: x86: Correct the binman symbols for SPL

These symbols are incorrect, meaning that binman cannot find the
associated entry. This leads to errors like:

binman: Section '/binman/simple-bin': Symbol '_binman_spl_prop_size'
   in entry '/binman/simple-bin/u-boot-spl/u-boot-spl-nodtb':
   Entry 'spl' not found in list (mkimage,u-boot-spl-nodtb,
   u-boot-spl-bss-pad,u-boot-spl-dtb,u-boot-spl,u-boot-img,main-section)

Fix it.

Signed-off-by: Simon Glass <sjg@chromium.org>

arch/x86/dts/u-boot.dtsi

@@ -37,7 +37,7 @@
 	u-boot-tpl-dtb {
 	};
 #endif
-	spl {
+	u-boot-spl {
 		type = "u-boot-spl";
 		offset = <CONFIG_X86_OFFSET_SPL>;
 	};

common/spl/spl.c

@@ -54,8 +54,8 @@ binman_sym_declare(ulong, u_boot_any, image_pos);
 binman_sym_declare(ulong, u_boot_any, size);
 
 #ifdef CONFIG_TPL
-binman_sym_declare(ulong, spl, image_pos);
-binman_sym_declare(ulong, spl, size);
+binman_sym_declare(ulong, u_boot_spl, image_pos);
+binman_sym_declare(ulong, u_boot_spl, size);
 #endif
 
 /* Define board data structure */
@@ -143,14 +143,14 @@ void spl_fixup_fdt(void *fdt_blob)
 ulong spl_get_image_pos(void)
 {
 	return spl_phase() == PHASE_TPL ?
-		binman_sym(ulong, spl, image_pos) :
+		binman_sym(ulong, u_boot_spl, image_pos) :
 		binman_sym(ulong, u_boot_any, image_pos);
 }
 
 ulong spl_get_image_size(void)
 {
 	return spl_phase() == PHASE_TPL ?
-		binman_sym(ulong, spl, size) :
+		binman_sym(ulong, u_boot_spl, size) :
 		binman_sym(ulong, u_boot_any, size);
 }
 

include/spl.h

@@ -269,8 +269,8 @@ struct spl_load_info {
  */
 binman_sym_extern(ulong, u_boot_any, image_pos);
 binman_sym_extern(ulong, u_boot_any, size);
-binman_sym_extern(ulong, spl, image_pos);
-binman_sym_extern(ulong, spl, size);
+binman_sym_extern(ulong, u_boot_spl, image_pos);
+binman_sym_extern(ulong, u_boot_spl, size);
 
 /**
  * spl_get_image_pos() - get the image position of the next phase