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/brxre1_defconfig b/configs/brxre1_defconfig
index 9a4deff..91c2560 100644
--- a/configs/brxre1_defconfig
+++ b/configs/brxre1_defconfig
@@ -34,8 +34,8 @@
 # CONFIG_DISPLAY_BOARDINFO is not set
 CONFIG_ARCH_MISC_INIT=y
 CONFIG_SPL_SYS_MALLOC_SIMPLE=y
-CONFIG_SYS_SPL_MALLOC=y
-CONFIG_SYS_SPL_MALLOC_SIZE=0x500000
+CONFIG_SPL_SYS_MALLOC=y
+CONFIG_SPL_SYS_MALLOC_SIZE=0x500000
 CONFIG_SPL_I2C=y
 # CONFIG_SPL_NAND_SUPPORT is not set
 CONFIG_SPL_POWER=y