ARM: sunxi: Remove Makefile.boot file

Since we've been a multi-platform enabled kernel from the beginning,
Makefile.boot has always been dead code.

Remove it.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
diff --git a/arch/arm/mach-sunxi/Makefile.boot b/arch/arm/mach-sunxi/Makefile.boot
deleted file mode 100644
index 46d4cf0..0000000
--- a/arch/arm/mach-sunxi/Makefile.boot
+++ /dev/null
@@ -1 +0,0 @@
-zreladdr-$(CONFIG_ARCH_SUNXI)	+= 0x40008000