Kconfig: Move SPL settings into their own file

Move the SPL settings into common/spl where most of the SPL code is kept.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/xilinx_zynqmp_zc1751_xm019_dc5_defconfig b/configs/xilinx_zynqmp_zc1751_xm019_dc5_defconfig
index 0e82bf2..2fbba0b 100644
--- a/configs/xilinx_zynqmp_zc1751_xm019_dc5_defconfig
+++ b/configs/xilinx_zynqmp_zc1751_xm019_dc5_defconfig
@@ -4,11 +4,11 @@
 CONFIG_SYS_MALLOC_F_LEN=0x8000
 CONFIG_SYS_TEXT_BASE=0x8000000
 CONFIG_DEFAULT_DEVICE_TREE="zynqmp-zc1751-xm019-dc5"
-CONFIG_SPL=y
-CONFIG_SPL_SYS_MALLOC_SIMPLE=y
 CONFIG_FIT=y
 CONFIG_FIT_VERBOSE=y
 CONFIG_SPL_LOAD_FIT=y
+CONFIG_SPL=y
+CONFIG_SPL_SYS_MALLOC_SIMPLE=y
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="ZynqMP> "
 # CONFIG_CMD_IMLS is not set