powerpc/.../ss555.cfg: Disable per function sections.

updates #2563.

c/src/lib/libbsp/powerpc/ss555/make/custom/ss555.cfg

@@ -20,9 +20,11 @@ CPU_CFLAGS = -mcpu=$(GCC_CPU_MODEL) -D$(RTEMS_CPU_MODEL)
 
 # optimize flag: typically -O2
 CFLAGS_OPTIMIZE_V = -O2 -g -fno-keep-inline-functions
-CFLAGS_OPTIMIZE_V += -ffunction-sections -fdata-sections
 
-LDFLAGS = -Wl,--gc-sections
+# FIXME: Disabled because linkcmds lacks proper KEEP() directives. See #2561.
+# The following two lines enable compiling and linking on per element.
+# CFLAGS_OPTIMIZE_V += -ffunction-sections -fdata-sections
+# LDFLAGS = -Wl,--gc-sections
 
 define bsp-post-link
 	$(default-bsp-post-link)