ACPI: processor: idle: Expose max_cstate/nocst/bm_check_disable read-only in sysfs

This will allow super users to verify the module parameters in question
when changed via kernel command line.

The parameters "nocst/bm_check_disable" are only used for enable/disable,
so change them from integer to bool.
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/processor_idle.c

@@ -37,11 +37,11 @@
 #define ACPI_IDLE_STATE_START	(IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
 
 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
-module_param(max_cstate, uint, 0000);
-static unsigned int nocst __read_mostly;
-module_param(nocst, uint, 0000);
-static int bm_check_disable __read_mostly;
-module_param(bm_check_disable, uint, 0000);
+module_param(max_cstate, uint, 0400);
+static bool nocst __read_mostly;
+module_param(nocst, bool, 0400);
+static bool bm_check_disable __read_mostly;
+module_param(bm_check_disable, bool, 0400);
 
 static unsigned int latency_factor __read_mostly = 2;
 module_param(latency_factor, uint, 0644);