of: clean-up unnecessary libfdt include paths

With the libfdt include fixups to use "" instead of <> in the
latest dtc import in commit 4760597 (scripts/dtc: Update to upstream
version 9d3649bd3be245c9), it is no longer necessary to add explicit
include paths to use libfdt. Remove these across the kernel.

Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Grant Likely <grant.likely@linaro.org>
Cc: linux-mips@linux-mips.org
Cc: linuxppc-dev@lists.ozlabs.org

drivers/firmware/efi/libstub/Makefile

@@ -24,8 +24,6 @@ KASAN_SANITIZE			:= n
 lib-y				:= efi-stub-helper.o
 lib-$(CONFIG_EFI_ARMSTUB)	+= arm-stub.o fdt.o
 
-CFLAGS_fdt.o			+= -I$(srctree)/scripts/dtc/libfdt/
-
 #
 # arm64 puts the stub in the kernel proper, which will unnecessarily retain all
 # code indefinitely unless it is annotated as __init/__initdata/__initconst etc.