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/k2e_evm_defconfig b/configs/k2e_evm_defconfig
index d0410a4..ab8dea3 100644
--- a/configs/k2e_evm_defconfig
+++ b/configs/k2e_evm_defconfig
@@ -36,8 +36,8 @@
 CONFIG_SPL_BSS_START_ADDR=0xc10fff8
 CONFIG_SPL_BSS_MAX_SIZE=0x8000
 # CONFIG_SPL_SHARES_INIT_SP_ADDR is not set
-CONFIG_SYS_SPL_MALLOC=y
-CONFIG_SYS_SPL_MALLOC_SIZE=0x8000
+CONFIG_SPL_SYS_MALLOC=y
+CONFIG_SPL_SYS_MALLOC_SIZE=0x8000
 CONFIG_SPL_I2C=y
 CONFIG_SPL_NAND_DRIVERS=y
 CONFIG_SPL_NAND_ECC=y