x86: baytrail: Add .gitignore for ACPI enabled boards

Let git ignore dsdt.aml, dsdt.asl.tmp and dsdt.c files.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Tested-by: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/board/intel/minnowmax/.gitignore b/board/intel/minnowmax/.gitignore
new file mode 100644
index 0000000..6eb8a54
--- /dev/null
+++ b/board/intel/minnowmax/.gitignore
@@ -0,0 +1,3 @@
+dsdt.aml
+dsdt.asl.tmp
+dsdt.c