jiffies: Remove obsolete SHIFTED_HZ comment

b3c869d ("jiffies: Remove compile time assumptions about
CLOCK_TICK_RATE") removed the last definition of SHIFTED_HZ but left
behind comments about it.  Remove the comments as well.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250825203425.796034-1-helgaas@kernel.org

Author: bjorn-helgaas

include/linux/jiffies.h

@@ -61,7 +61,7 @@
 
 extern void register_refined_jiffies(long clock_tick_rate);
 
-/* TICK_USEC is the time between ticks in usec assuming SHIFTED_HZ */
+/* TICK_USEC is the time between ticks in usec */
 #define TICK_USEC ((USEC_PER_SEC + HZ/2) / HZ)
 
 /* USER_TICK_USEC is the time between ticks in usec assuming fake USER_HZ */

include/vdso/jiffies.h

@@ -5,7 +5,7 @@
 #include <asm/param.h>			/* for HZ */
 #include <vdso/time64.h>
 
-/* TICK_NSEC is the time between ticks in nsec assuming SHIFTED_HZ */
+/* TICK_NSEC is the time between ticks in nsec */
 #define TICK_NSEC ((NSEC_PER_SEC+HZ/2)/HZ)
 
 #endif /* __VDSO_JIFFIES_H */