spl: use TPL_SYS_MALLOC_F_LEN for TPL

The (upstream) changes to break up SYS_MALLOC_F_LEN for the full
U-Boot and the SPL stage, break TPL (if simple malloc is enabled in
TPL).

This adds support for a TPL-variant of SYS_MALLOC_F_LEN:
- adds TPL_SYS_MALLOC_F_LEN
- rewrites a test for CONFIG_SPL_SYS_MALLOC_F_LEN to access
  CONFIG_VAL(SYS_MALLOC_F_LEN)

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/common/spl/spl.c b/common/spl/spl.c
index c56cc6f..bdb681f 100644
--- a/common/spl/spl.c
+++ b/common/spl/spl.c
@@ -486,7 +486,7 @@
 	gd_t *new_gd;
 	ulong ptr = CONFIG_SPL_STACK_R_ADDR;
 
-#if defined(CONFIG_SPL_SYS_MALLOC_SIMPLE) && CONFIG_SPL_SYS_MALLOC_F_LEN
+#if defined(CONFIG_SPL_SYS_MALLOC_SIMPLE) && CONFIG_VAL(SYS_MALLOC_F_LEN)
 	if (CONFIG_SPL_STACK_R_MALLOC_SIMPLE_LEN) {
 		ptr -= CONFIG_SPL_STACK_R_MALLOC_SIMPLE_LEN;
 		gd->malloc_base = ptr;