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/configs/am335x_guardian_defconfig b/configs/am335x_guardian_defconfig
index 7c4085d..01d848c 100644
--- a/configs/am335x_guardian_defconfig
+++ b/configs/am335x_guardian_defconfig
@@ -31,8 +31,8 @@
 CONFIG_SYS_CONSOLE_INFO_QUIET=y
 CONFIG_ARCH_MISC_INIT=y
 # CONFIG_SPL_RAW_IMAGE_SUPPORT is not set
-CONFIG_SYS_SPL_MALLOC=y
-CONFIG_SYS_SPL_MALLOC_SIZE=0x800000
+CONFIG_SPL_SYS_MALLOC=y
+CONFIG_SPL_SYS_MALLOC_SIZE=0x800000
 # CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_USE_SECTOR is not set
 CONFIG_SPL_ENV_SUPPORT=y
 CONFIG_SPL_ETH=y