powerpc/kasan: Disable KCOV in KASAN code

As per the generic KASAN code in mm/kasan, disable KCOV with
KCOV_INSTRUMENT := n in the makefile.

This fixes a ppc64 boot hang when KCOV and KASAN are enabled.
kasan_early_init() gets called before a PACA is initialised, but the
KCOV hook expects a valid PACA.

Suggested-by: Christophe Leroy <[email protected]>
Signed-off-by: Benjamin Gray <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://msgid.link/[email protected]

Author: BenjaminGrayNp1

arch/powerpc/mm/kasan/Makefile

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 
 KASAN_SANITIZE := n
+KCOV_INSTRUMENT := n
 
 obj-$(CONFIG_PPC32)		+= init_32.o
 obj-$(CONFIG_PPC_8xx)		+= 8xx.o