kernel: Block HIP detection through HIP_PATH=none

The issue of the multi-lined, wrongly expanded LINUX_COMPILER macro is
back (at least for kernel 4.14).

Funnily enough, setting "--hip-path=/dev/null", or using any other file
or directory that exists, would still make clang happy and give a
message stating that it detected HIP anyways:

  Found HIP installation: /dev/null, version 3.5.0

To get around this issue, without doing monumental backports and
avoiding warnings from "-Wunused-command-line-argument", set
"HIP_PATH=none", where "none" simply indicates a non-existing
file/directory.

Change-Id: Ia97d69425716d28208ba344bde79a910e5f75c84
Signed-off-by: voidanix <voidanix@keyedlimepie.org>

config/BoardConfigKernel.mk

@@ -113,7 +113,7 @@ KERNEL_MAKE_FLAGS :=
 KERNEL_MAKE_FLAGS += -j$(shell getconf _NPROCESSORS_ONLN)
 
 TOOLS_PATH_OVERRIDE := \
-    PERL5LIB=$(BUILD_TOP)/prebuilts/tools-lineage/common/perl-base
+    HIP_PATH=none PERL5LIB=$(BUILD_TOP)/prebuilts/tools-lineage/common/perl-base
 
 ifneq ($(KERNEL_NO_GCC), true)
     GCC_PREBUILTS := $(BUILD_TOP)/prebuilts/gcc/$(HOST_PREBUILT_TAG)