platform/x86: intel_pmc_core: transform Pkg C-state residency from TSC ticks into microseconds

Refer to the Intel SDM Vol.4, the package C-state residency counters
of modern IA micro-architecture are all ticking in TSC frequency,
hence we can apply simple math to transform the ticks into microseconds.
i.e.,
residency (ms) = count / tsc_khz
residency (us) = count / tsc_khz * 1000

This also aligns to other sysfs debug entries of residency counter in
the same metric in microseconds, benefits reading and scripting.

v2: restore the accidentally deleted newline, no function change.
v3: apply kernel do_div() macro to calculate division
Signed-off-by: Harry Pan <harry.pan@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

drivers/platform/x86/intel_pmc_core.c

@@ -26,6 +26,7 @@
 #include <asm/cpu_device_id.h>
 #include <asm/intel-family.h>
 #include <asm/msr.h>
+#include <asm/tsc.h>
 
 #include "intel_pmc_core.h"
 
@@ -740,7 +741,9 @@ static int pmc_core_pkgc_show(struct seq_file *s, void *unused)
 		if (rdmsrl_safe(map[index].bit_mask, &pcstate_count))
 			continue;
 
-		seq_printf(s, "%-8s : 0x%llx\n", map[index].name,
+		pcstate_count *= 1000;
+		do_div(pcstate_count, tsc_khz);
+		seq_printf(s, "%-8s : %llu\n", map[index].name,
 			   pcstate_count);
 	}