powerpc/mpc85xx: Explain TLB unmapped memory message

Currently U-Boot SPL prints just generic message "2 GiB left unmapped".
Change it to more detailed "2 GiB of DDR memory left unmapped in U-Boot".
This is just U-Boot configuration and operating system may map more (or
also less) memory.

Signed-off-by: Pali Rohár <pali@kernel.org>
diff --git a/arch/powerpc/cpu/mpc85xx/tlb.c b/arch/powerpc/cpu/mpc85xx/tlb.c
index ab61649..4e4ecb4 100644
--- a/arch/powerpc/cpu/mpc85xx/tlb.c
+++ b/arch/powerpc/cpu/mpc85xx/tlb.c
@@ -312,7 +312,7 @@
 	if (size || memsize > CONFIG_MAX_MEM_MAPPED) {
 		print_size(memsize > CONFIG_MAX_MEM_MAPPED ?
 			   memsize - CONFIG_MAX_MEM_MAPPED + size : size,
-			   " left unmapped\n");
+			   " of DDR memory left unmapped in U-Boot\n");
 	}
 
 	return memsize_in_meg;