configs: net: dm9000: Move new Kconfig option to board configs

Drop legacy #define CONFIG_DRIVER_DM9000 from board include/configs/
and enable the same in Kconfig configs/ .

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Joe Hershberger <joe.hershberger@ni.com>
Cc: Ramon Fried <rfried.dev@gmail.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
diff --git a/configs/devkit8000_defconfig b/configs/devkit8000_defconfig
index e009f21..2bff7df 100644
--- a/configs/devkit8000_defconfig
+++ b/configs/devkit8000_defconfig
@@ -57,6 +57,7 @@
 CONFIG_SYS_NAND_BUSWIDTH_16BIT=y
 CONFIG_SYS_NAND_U_BOOT_LOCATIONS=y
 CONFIG_SYS_NAND_U_BOOT_OFFS=0x80000
+CONFIG_DRIVER_DM9000=y
 CONFIG_CONS_INDEX=3
 CONFIG_JFFS2_NAND=y
 CONFIG_OF_LIBFDT=y