arm64: constify icache_policy_str[]

The icache_policy_str[] array contains compile-time constant data, and
is never intentionally modified, so let's mark it as const.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>

arch/arm64/kernel/cpuinfo.c

@@ -33,7 +33,7 @@
 DEFINE_PER_CPU(struct cpuinfo_arm64, cpu_data);
 static struct cpuinfo_arm64 boot_cpu_data;
 
-static char *icache_policy_str[] = {
+static const char *icache_policy_str[] = {
 	[0 ... ICACHE_POLICY_PIPT]	= "RESERVED/UNKNOWN",
 	[ICACHE_POLICY_VIPT]		= "VIPT",
 	[ICACHE_POLICY_PIPT]		= "PIPT",