nios2: allow STANDALONE_LOAD_ADDR overriding

This patch allows users to override default STANDALONE_LOAD_ADDR.
The gcclibdir path was duplicated in the standalone Makefile and
can be removed.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Signed-off-by: Scott McNutt <smcnutt@psyent.com>

arch/nios2/config.mk

@@ -24,7 +24,7 @@
 
 CROSS_COMPILE ?= nios2-elf-
 
-STANDALONE_LOAD_ADDR = 0x02000000 -L $(gcclibdir)
+STANDALONE_LOAD_ADDR ?= 0x02000000
 
 PLATFORM_CPPFLAGS += -DCONFIG_NIOS2 -D__NIOS2__
 PLATFORM_CPPFLAGS += -G0