sparc: Fix out-of-tree building

It isn't clear why the sparc cpu Makefile has its own compile line, but
it does not work correctly with an out-of-tree build. Removing it fixes
this problem. Perhaps it does not introduce others.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/sparc/cpu/leon2/Makefile b/arch/sparc/cpu/leon2/Makefile
index a9a18eb..d4dc397 100644
--- a/arch/sparc/cpu/leon2/Makefile
+++ b/arch/sparc/cpu/leon2/Makefile
@@ -43,13 +43,6 @@
 # defines $(obj).depend target
 include $(SRCTREE)/rules.mk
 
-$(START): $(START:.o=.S)
-	$(CC) -D__ASSEMBLY__ $(DBGFLAGS) $(OPTFLAGS) -D__KERNEL__ \
-	-DCONFIG_SYS_TEXT_BASE=$(CONFIG_SYS_TEXT_BASE) -I$(TOPDIR)/include \
-	-fno-builtin -ffreestanding -nostdinc -isystem $(gccincdir) -pipe \
-	$(PLATFORM_CPPFLAGS) -Wall -Wstrict-prototypes \
-	-I$(TOPDIR)/board -c -o $(START) $(START:.o=.S)
-
 sinclude $(obj).depend
 
 #########################################################################
diff --git a/arch/sparc/cpu/leon3/Makefile b/arch/sparc/cpu/leon3/Makefile
index 16d3377..1d051e1 100644
--- a/arch/sparc/cpu/leon3/Makefile
+++ b/arch/sparc/cpu/leon3/Makefile
@@ -43,13 +43,6 @@
 # defines $(obj).depend target
 include $(SRCTREE)/rules.mk
 
-$(START): $(START:.o=.S)
-	$(CC) -D__ASSEMBLY__ $(DBGFLAGS) $(OPTFLAGS) -D__KERNEL__ \
-	-DCONFIG_SYS_TEXT_BASE=$(CONFIG_SYS_TEXT_BASE) -I$(TOPDIR)/include \
-	-fno-builtin -ffreestanding -nostdinc -isystem $(gccincdir) -pipe \
-	$(PLATFORM_CPPFLAGS) -Wall -Wstrict-prototypes \
-	-I$(TOPDIR)/board -c -o $(START) $(START:.o=.S)
-
 sinclude $(obj).depend
 
 #########################################################################