support CONFIG_SYS_LDSCRIPT on ARM

Signed-off-by: Michael Schwingen <michael@schwingen.org>
diff --git a/arch/arm/config.mk b/arch/arm/config.mk
index ec1b420..788d4c1 100644
--- a/arch/arm/config.mk
+++ b/arch/arm/config.mk
@@ -62,6 +62,13 @@
 endif
 endif
 
+ifdef CONFIG_SYS_LDSCRIPT
+# need to strip off double quotes
+LDSCRIPT := $(subst ",,$(CONFIG_SYS_LDSCRIPT))
+else
+LDSCRIPT := $(SRCTREE)/$(CPUDIR)/u-boot.lds
+endif
+
 # needed for relocation
 ifndef CONFIG_NAND_SPL
 LDFLAGS_u-boot += -pie