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/openpiton_riscv64_spl_defconfig b/configs/openpiton_riscv64_spl_defconfig
index 9272bf6..c0ec9ed 100644
--- a/configs/openpiton_riscv64_spl_defconfig
+++ b/configs/openpiton_riscv64_spl_defconfig
@@ -29,7 +29,7 @@
 # CONFIG_SPL_LEGACY_IMAGE_FORMAT is not set
 CONFIG_SPL_SYS_MALLOC_SIMPLE=y
 # CONFIG_SPL_SHARES_INIT_SP_ADDR is not set
-CONFIG_SYS_SPL_MALLOC=y
+CONFIG_SPL_SYS_MALLOC=y
 # CONFIG_SPL_BANNER_PRINT is not set
 CONFIG_SPL_CPU=y
 CONFIG_SPL_FS_EXT4=y