arm: socfpga: Move wrappers into platform directory

Move the wrappers for QTS-generated files into platform directory
out of the board directory. The trick here is to add -I to CFLAGS
such that it points to the board directory in source tree and thus
the qts/ directory there is still reachable.

Signed-off-by: Marek Vasut <marex@denx.de>
diff --git a/board/altera/socfpga/Makefile b/board/altera/socfpga/Makefile
index 5a15c71..86f9b78 100644
--- a/board/altera/socfpga/Makefile
+++ b/board/altera/socfpga/Makefile
@@ -6,6 +6,4 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-obj-y	:= socfpga.o wrap_pll_config.o
-obj-$(CONFIG_SPL_BUILD) += wrap_iocsr_config.o wrap_pinmux_config.o	\
-			   wrap_sdram_config.o
+obj-y	:= socfpga.o