lpc32xx: devkit3250: add spl build support

The change adds SPL build support to Timll DevKit3250 board, the
generated SPL image can be uploaded over UART5, JTAG or stored on
NAND. SPL is designed to load U-boot image from NAND.

All new NAND chip defines in board configuration are needed by
SPL NAND "simple" framework, the framework is used to reduce
potentially duplicated code from LPC32xx SLC NAND driver.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 8b8269f..f2eb09f 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -121,6 +121,7 @@
 config TARGET_DEVKIT3250
 	bool "Support devkit3250"
 	select CPU_ARM926EJS
+	select SUPPORT_SPL
 
 config TARGET_WORK_92105
 	bool "Support work_92105"