MIPS: fix linking of standalone programs

Use the global MIPS specific u-boot.lds for linking standalone programs
instead of the outdated ones in examples/standalone/. Also pass --gc-sections
in LDFLAGS_STANDALONE to optimize the size of standalone programs.
Finally remove the deprecated config.mk files in arch/mips/cpu/mips[32,64]/.

Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
diff --git a/arch/mips/config.mk b/arch/mips/config.mk
index 22223a0f..9d3a845 100644
--- a/arch/mips/config.mk
+++ b/arch/mips/config.mk
@@ -25,12 +25,14 @@
 PLATFORM_CPPFLAGS	+= -mabi=32
 PLATFORM_LDFLAGS	+= -m $(32bit-emul)
 OBJCOPYFLAGS		+= -O $(32bit-bfd)
+CONFIG_STANDALONE_LOAD_ADDR	?= 0x80200000
 endif
 
 ifdef CONFIG_64BIT
 PLATFORM_CPPFLAGS	+= -mabi=64
 PLATFORM_LDFLAGS	+= -m$(64bit-emul)
 OBJCOPYFLAGS		+= -O $(64bit-bfd)
+CONFIG_STANDALONE_LOAD_ADDR	?= 0xffffffff80200000
 endif
 
 PLATFORM_CPPFLAGS += -D__MIPS__
@@ -65,3 +67,5 @@
 PLATFORM_RELFLAGS		+= -ffunction-sections -fdata-sections
 LDFLAGS_FINAL			+= --gc-sections
 OBJCOPYFLAGS			+= -j .text -j .rodata -j .data -j .u_boot_list
+
+LDFLAGS_STANDALONE		+= --gc-sections