powerpc: mpc85xx: Rename _start_e500 symbol to _start

The real entry point is _start_e500. There is no _start symbol at all. So
rename _start_e500 to _start for convension that _start symbol is used as
entry point.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
diff --git a/arch/powerpc/cpu/mpc85xx/u-boot.lds b/arch/powerpc/cpu/mpc85xx/u-boot.lds
index 22bbac5..17a0e63 100644
--- a/arch/powerpc/cpu/mpc85xx/u-boot.lds
+++ b/arch/powerpc/cpu/mpc85xx/u-boot.lds
@@ -16,7 +16,7 @@
 #endif
 
 OUTPUT_ARCH(powerpc)
-ENTRY(_start_e500)
+ENTRY(_start)
 
 PHDRS
 {