twister: add missing includes

Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
diff --git a/board/technexion/twister/twister.c b/board/technexion/twister/twister.c
index 054e7cc..a4aed3b 100644
--- a/board/technexion/twister/twister.c
+++ b/board/technexion/twister/twister.c
@@ -16,6 +16,8 @@
 #include <asm/omap_gpio.h>
 #include <asm/arch/mmc_host_def.h>
 #include <i2c.h>
+#include <spl.h>
+#include <mmc.h>
 #include <asm/gpio.h>
 #ifdef CONFIG_USB_EHCI
 #include <usb.h>