spl: Kconfig: Escape '$(ARCH)' in LDSCRIPT entries

The default SPL / TPL linker script is in the $(ARCH) directory.  The
way we use this today works but isn't ideal.  With an update to Kconfig
to re-sync with the Linux Kernel, we need to escape the '$' here so that
it will end up being evaluated by make.

Cc: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
diff --git a/common/spl/Kconfig b/common/spl/Kconfig
index b03a476..9d52b75 100644
--- a/common/spl/Kconfig
+++ b/common/spl/Kconfig
@@ -139,7 +139,7 @@
 
 config SPL_LDSCRIPT
 	string "Linker script for the SPL stage"
-	default "arch/$(ARCH)/cpu/u-boot-spl.lds"
+	default "arch/\$(ARCH)/cpu/u-boot-spl.lds"
 	help
 	  The SPL stage will usually require a different linker-script
 	  (as it runs from a different memory region) than the regular
@@ -1306,7 +1306,7 @@
         string "Linker script for the TPL stage"
 	depends on TPL
 	default "arch/arm/cpu/armv8/u-boot-spl.lds" if ARM64
-	default "arch/$(ARCH)/cpu/u-boot-spl.lds"
+	default "arch/\$(ARCH)/cpu/u-boot-spl.lds"
 	help
 	  The TPL stage will usually require a different linker-script
 	  (as it runs from a different memory region) than the regular