[bsp][asm9260t] Fix link script ENTRY symbol.

bsp/asm9260t/link_scripts/sdram.ld

@@ -1,6 +1,6 @@
 OUTPUT_FORMAT("elf32-littlearm", "elf32-littlearm", "elf32-littlearm")
 OUTPUT_ARCH(arm)
-ENTRY(entry)
+ENTRY(start)
 SECTIONS
 {
     . = 0x20000000;