cpuidle: clean up dead dependencies on CPU_IDLE in Kconfig

The Kconfig in the parent directory already has the first 'if CPU_IDLE'
gating the inclusion of this Kconfig, meaning that the 'depends on
CPUIDLE' statements in these config options are effectively dead code.

Leave the 'if CPU_IDLE...endif' condition, and remove the individual
'depends on' statements in Kconfig.mips and Kconfig.powerpc

This dead code was found by kconfirm, a static analysis tool for
Kconfig.

Signed-off-by: Julian Braha <julianbraha@gmail.com>
[ rjw: Subject and changelog edits ]
Link: https://patch.msgid.link/20260331074920.41269-1-julianbraha@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: julianbraha

drivers/cpuidle/Kconfig

@@ -81,7 +81,7 @@ config HALTPOLL_CPUIDLE
 	 before halting in the guest (more efficient than polling in the
 	 host via halt_poll_ns for some scenarios).
 
-endif
+endif # CPU_IDLE
 
 config ARCH_NEEDS_CPU_IDLE_COUPLED
 	def_bool n

drivers/cpuidle/Kconfig.mips

@@ -4,7 +4,7 @@
 #
 config MIPS_CPS_CPUIDLE
 	bool "CPU Idle driver for MIPS CPS platforms"
-	depends on CPU_IDLE && MIPS_CPS
+	depends on MIPS_CPS
 	depends on SYS_SUPPORTS_MIPS_CPS
 	select ARCH_NEEDS_CPU_IDLE_COUPLED if MIPS_MT || CPU_MIPSR6
 	select GENERIC_CLOCKEVENTS_BROADCAST if SMP

drivers/cpuidle/Kconfig.powerpc

@@ -4,7 +4,6 @@
 #
 config PSERIES_CPUIDLE
 	bool "Cpuidle driver for pSeries platforms"
-	depends on CPU_IDLE
 	depends on PPC_PSERIES
 	default y
 	help
@@ -13,7 +12,6 @@ config PSERIES_CPUIDLE
 
 config POWERNV_CPUIDLE
 	bool "Cpuidle driver for powernv platforms"
-	depends on CPU_IDLE
 	depends on PPC_POWERNV
 	default y
 	help