spl: Use CONFIG_SPL... instead of CONFIG_..._SPL_...

We like to put the SPL first so it is clear that it relates to SPL. Rename
various malloc-related options which have crept in, to stick to this
convention.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Reviewed-by: Martyn Welch <martyn.welch@collabora.com>
Reviewed-by: Svyatoslav Ryhel <clamor95@gmail.com>
diff --git a/drivers/core/Kconfig b/drivers/core/Kconfig
index f0d848f..4c5a00f 100644
--- a/drivers/core/Kconfig
+++ b/drivers/core/Kconfig
@@ -14,7 +14,7 @@
 	help
 	  Enable driver model in SPL. You will need to provide a
 	  suitable malloc() implementation. If you are not using the
-	  full malloc() enabled by CFG_SYS_SPL_MALLOC_START,
+	  full malloc() enabled by CFG_SPL_SYS_MALLOC_START,
 	  consider using CONFIG_SPL_SYS_MALLOC_SIMPLE. In that case you
 	  must provide CONFIG_SPL_SYS_MALLOC_F_LEN to set the size.
 	  In most cases driver model will only allocate a few uclasses
@@ -27,7 +27,7 @@
 	help
 	  Enable driver model in TPL. You will need to provide a
 	  suitable malloc() implementation. If you are not using the
-	  full malloc() enabled by CFG_SYS_SPL_MALLOC_START,
+	  full malloc() enabled by CFG_SPL_SYS_MALLOC_START,
 	  consider using CONFIG_TPL_SYS_MALLOC_SIMPLE. In that case you
 	  must provide CONFIG_SPL_SYS_MALLOC_F_LEN to set the size.
 	  In most cases driver model will only allocate a few uclasses
@@ -42,7 +42,7 @@
 	help
 	  Enable driver model in VPL. You will need to provide a
 	  suitable malloc() implementation. If you are not using the
-	  full malloc() enabled by CFG_SYS_SPL_MALLOC_START,
+	  full malloc() enabled by CFG_SPL_SYS_MALLOC_START,
 	  consider using CONFIG_SPL_SYS_MALLOC_SIMPLE.
 
 config DM_WARN