spl: add debug print for early malloc usage

To find out how big the early malloc heap must be in SPL, add a debug
print statement that dumps its usage before switching to relocated heap
in spl_relocate_stack_gd() via CONFIG_SPL_STACK_R_MALLOC_SIMPLE_LEN.

Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
diff --git a/common/spl/spl.c b/common/spl/spl.c
index 2e2af1b..88d4b8a 100644
--- a/common/spl/spl.c
+++ b/common/spl/spl.c
@@ -728,6 +728,8 @@
 
 #if defined(CONFIG_SPL_SYS_MALLOC_SIMPLE) && CONFIG_VAL(SYS_MALLOC_F_LEN)
 	if (CONFIG_SPL_STACK_R_MALLOC_SIMPLE_LEN) {
+		debug("SPL malloc() before relocation used 0x%lx bytes (%ld KB)\n",
+		      gd->malloc_ptr, gd->malloc_ptr / 1024);
 		ptr -= CONFIG_SPL_STACK_R_MALLOC_SIMPLE_LEN;
 		gd->malloc_base = ptr;
 		gd->malloc_limit = CONFIG_SPL_STACK_R_MALLOC_SIMPLE_LEN;