Convert CONFIG_MAC_ADDR_IN_SPIFLASH et al to Kconfig

This converts the following to Kconfig:
   CONFIG_MAC_ADDR_IN_SPIFLASH
   CONFIG_MAC_ADDR_IN_EEPROM

Signed-off-by: Adam Ford <aford173@gmail.com>
diff --git a/board/davinci/da8xxevm/Kconfig b/board/davinci/da8xxevm/Kconfig
index d49d244..bb1188b 100644
--- a/board/davinci/da8xxevm/Kconfig
+++ b/board/davinci/da8xxevm/Kconfig
@@ -9,6 +9,30 @@
 config SYS_CONFIG_NAME
 	default "da850evm"
 
+menuconfig DA850_MAC
+	bool "Use MAC Address"
+	default y
+
+if DA850_MAC
+config MAC_ADDR_IN_SPIFLASH
+	bool "MAC address in SPI Flash"
+	default y
+	help
+	  The OMAP-L138 and AM1808 SoM are programmed with
+	  their MAC address in SPI Flash from the factory
+	  Enable this option to read the MAC from SPI Flash
+
+config MAC_ADDR_IN_EEPROM
+	bool "MAC address in EEPROM"
+	help
+	  The DA850 EVM comes with SoM are programmed with
+	  their MAC address in SPI Flash from the factory,
+	  but the kit has an optional expansion board with
+	  EEPROM available.  Enable this option to read the
+	  MAC from the EEPROM
+
+endif
+
 endif
 
 if TARGET_OMAPL138_LCDK