x86/mwait-idle: Remove unused driver version constant

The MWAIT_IDLE_VERSION constant has not been updated since 2016 and serves
no useful purpose. The driver version is implicitly defined by the
hypervisor version, making this constant redundant.

Remove the constant to eliminate potential confusion about version
tracking.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Link: https://patch.msgid.link/20251215111229.132705-1-dedekind1@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Origin: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 25ff69011ddf

Adjust description to fit our code base.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>

xen/arch/x86/cpu/mwait-idle.c

@@ -58,7 +58,6 @@
 
 #include <acpi/cpufreq/cpufreq.h>
 
-#define MWAIT_IDLE_VERSION "0.4.1"
 #undef PREFIX
 #define PREFIX "mwait-idle: "
 
@@ -1636,9 +1635,6 @@ static int __init mwait_idle_probe(void)
 	if (boot_cpu_has(X86_FEATURE_XEN_ARAT))
 		lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;
 
-	pr_debug(PREFIX "v" MWAIT_IDLE_VERSION " model %#x\n",
-		 boot_cpu_data.model);
-
 	pr_debug(PREFIX "lapic_timer_reliable_states %#x\n",
 		 lapic_timer_reliable_states);