.gitignore: move *.dtb and *.dtb.S patterns to the top-level .gitignore

Follow Linux commit 10b62a2f785a (".gitignore: move *.dtb and *.dtb.S
patterns to the top-level .gitignore").

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/.gitignore b/.gitignore
index 4d4c486..6bb0ade 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,6 +9,8 @@
 *.a
 *.bin
 *.cfgtmp
+*.dtb
+*.dtb.S
 *.elf
 *.exe
 *.gcda
diff --git a/arch/arc/dts/.gitignore b/arch/arc/dts/.gitignore
deleted file mode 100644
index b60ed20..0000000
--- a/arch/arc/dts/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-*.dtb
diff --git a/arch/arm/dts/.gitignore b/arch/arm/dts/.gitignore
deleted file mode 100644
index b60ed20..0000000
--- a/arch/arm/dts/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-*.dtb
diff --git a/arch/microblaze/dts/.gitignore b/arch/microblaze/dts/.gitignore
deleted file mode 100644
index b60ed20..0000000
--- a/arch/microblaze/dts/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-*.dtb
diff --git a/arch/mips/dts/.gitignore b/arch/mips/dts/.gitignore
deleted file mode 100644
index b60ed20..0000000
--- a/arch/mips/dts/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-*.dtb
diff --git a/arch/nios2/dts/.gitignore b/arch/nios2/dts/.gitignore
deleted file mode 100644
index b60ed20..0000000
--- a/arch/nios2/dts/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-*.dtb
diff --git a/arch/sandbox/dts/.gitignore b/arch/sandbox/dts/.gitignore
deleted file mode 100644
index b60ed20..0000000
--- a/arch/sandbox/dts/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-*.dtb
diff --git a/arch/x86/dts/.gitignore b/arch/x86/dts/.gitignore
deleted file mode 100644
index b60ed20..0000000
--- a/arch/x86/dts/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-*.dtb
diff --git a/dts/.gitignore b/dts/.gitignore
deleted file mode 100644
index 1b37180..0000000
--- a/dts/.gitignore
+++ /dev/null
@@ -1,2 +0,0 @@
-*.dtb
-*.dtb.S