config.mk: specify the exact path to standalone linker script

We want to change the build system to include config.mk
only from ./Makefile and spl/Makefile.
We must prepare for that in this commit.

$(src) is a moving target and not handy for our purpose.
We must replace it with a fixed path.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
diff --git a/arch/sparc/config.mk b/arch/sparc/config.mk
index e2327ec..6dbf20f 100644
--- a/arch/sparc/config.mk
+++ b/arch/sparc/config.mk
@@ -10,6 +10,6 @@
 endif
 
 CONFIG_STANDALONE_LOAD_ADDR ?= 0x00000000 -L $(gcclibdir) \
-			-T $(srctree)/$(src)/sparc.lds
+			       -T $(srctree)/examples/standalone/sparc.lds
 
 PLATFORM_CPPFLAGS += -DCONFIG_SPARC -D__sparc__