Makefile: Select objects by CONFIG_ rather than $(ARCH) or $(CPU)

Convert like follows:

 CPU mpc83xx  -> CONFIG_MPC83xx
 CPU mpc85xx  -> CONFIG_MPC85xx
 CPU mpc86xx  -> CONFIG_MPC86xx
 CPU mpc5xxx  -> CONFIG_MPC5xxx
 CPU mpc8xx   -> CONFIG_8xx
 CPU mpc8260  -> CONFIG_8260
 CPU ppc4xx   -> CONFIG_4xx
 CPU x86      -> CONFIG_X86
 ARCH x86     -> CONFIG_X86
 ARCH powerpc -> CONFIG_PPC

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
diff --git a/examples/standalone/Makefile b/examples/standalone/Makefile
index f4f102b..6e7500d 100644
--- a/examples/standalone/Makefile
+++ b/examples/standalone/Makefile
@@ -7,25 +7,27 @@
 
 include $(TOPDIR)/config.mk
 
-ELF-$(ARCH)  :=
-ELF-$(CPU)   :=
 ELF-y        := hello_world
 
 ELF-$(CONFIG_SMC91111)           += smc91111_eeprom
 ELF-$(CONFIG_SMC911X)            += smc911x_eeprom
 ELF-$(CONFIG_SPI_FLASH_ATMEL)    += atmel_df_pow2
-ELF-i386                         += 82559_eeprom
-ELF-mpc5xxx                      += interrupt
-ELF-mpc8xx                       += test_burst timer
-ELF-mpc8260                      += mem_to_mem_idma2intr
-ELF-ppc                          += sched
+# TODO:
+#   - Fix the warning of 82559_eeprom.c and uncomment the following
+# or
+#   - Delete 82559_eeprom.c and the following line
+#ELF-$(CONFIG_X86)                += 82559_eeprom
+ELF-$(CONFIG_MPC5xxx)            += interrupt
+ELF-$(CONFIG_8xx)                += test_burst timer
+ELF-$(CONFIG_8260)               += mem_to_mem_idma2intr
+ELF-$(CONFIG_PPC)                += sched
 
 #
 # Some versions of make do not handle trailing white spaces properly;
 # leading to build failures. The problem was found with GNU Make 3.80.
 # Using 'strip' as a workaround for the problem.
 #
-ELF := $(strip $(ELF-y) $(ELF-$(ARCH)) $(ELF-$(CPU)))
+ELF := $(strip $(ELF-y))
 
 SREC := $(addsuffix .srec,$(ELF))
 BIN  := $(addsuffix .bin,$(ELF))
@@ -34,11 +36,9 @@
 
 LIB	= $(obj)libstubs.o
 
-LIBAOBJS-$(ARCH)     :=
-LIBAOBJS-$(CPU)      :=
-LIBAOBJS-ppc         += $(ARCH)_longjmp.o $(ARCH)_setjmp.o
-LIBAOBJS-mpc8xx      += test_burst_lib.o
-LIBAOBJS := $(LIBAOBJS-$(ARCH)) $(LIBAOBJS-$(CPU))
+LIBAOBJS-$(CONFIG_PPC) += ppc_longjmp.o ppc_setjmp.o
+LIBAOBJS-$(CONFIG_8xx) += test_burst_lib.o
+LIBAOBJS := $(LIBAOBJS-y)
 
 LIBCOBJS = stubs.o