common: Drop linux/delay.h from common header

Move this uncommon header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/fpga/lattice.c b/drivers/fpga/lattice.c
index 2cf4a60..e292d99 100644
--- a/drivers/fpga/lattice.c
+++ b/drivers/fpga/lattice.c
@@ -15,6 +15,7 @@
 #include <malloc.h>
 #include <fpga.h>
 #include <lattice.h>
+#include <linux/delay.h>
 
 static lattice_board_specific_func *pfns;
 static const char *fpga_image;