cpufreq/amd-pstate: Add static asserts for EPP indices

In case a new index is introduced add a static assert to make sure
that strings and values are updated.

Reviewed-by: Gautham R. Shenoy <[e-mail]>
Signed-off-by: Mario Limonciello (AMD) <[e-mail]>

drivers/cpufreq/amd-pstate.c

···
 	EPP_INDEX_BALANCE_PERFORMANCE,
 	EPP_INDEX_BALANCE_POWERSAVE,
 	EPP_INDEX_POWERSAVE,
+	EPP_INDEX_MAX,
 };
 
 static const char * const energy_perf_strings[] = {
···
 	[EPP_INDEX_BALANCE_POWERSAVE] = "balance_power",
 	[EPP_INDEX_POWERSAVE] = "power",
 };
+static_assert(ARRAY_SIZE(energy_perf_strings) == EPP_INDEX_MAX);
 
 static unsigned int epp_values[] = {
 	[EPP_INDEX_DEFAULT] = 0,
···
 	[EPP_INDEX_BALANCE_POWERSAVE] = AMD_CPPC_EPP_BALANCE_POWERSAVE,
 	[EPP_INDEX_POWERSAVE] = AMD_CPPC_EPP_POWERSAVE,
 };
+static_assert(ARRAY_SIZE(epp_values) == EPP_INDEX_MAX);
 
 typedef int (*cppc_mode_transition_fn)(int);