sh: Use unified SCHED_MC Kconfig from arch/Kconfig

kconfiglint reports:

K008: config SCHED_MC has prompts in 2 separate definitions

SCHED_MC is defined in two places:

arch/Kconfig:73 — generic definition, depends on ARCH_SUPPORTS_SCHED_MC arch/sh/mm/Kconfig:185 — SH-specific definition, depends on SMP

The SH-specific SCHED_MC was introduced in commit 896f0c0e8e4e ("sh:
Support SCHED_MC for SH-X3 multi-cores.") before the generic ARCH_SUPPORTS_SCHED_MC mechanism existed in arch/Kconfig.

Commit 7bd291abe2da ("sched: Unify the SCHED_{SMT,CLUSTER,MC} Kconfig") consolidated SCHED_MC definitions across most architectures into the generic arch/Kconfig version. That commit did not touch SH because SH had not opted into the unified mechanism by selecting ARCH_SUPPORTS_SCHED_MC.

Complete the unification for SH by:
1. Adding select ARCH_SUPPORTS_SCHED_MC if SMP to the SUPERH config
2. Removing the SH-specific SCHED_MC from arch/sh/mm/Kconfig

This is functionally equivalent: both definitions depend on SMP (the generic one via ARCH_SUPPORTS_SCHED_MC, which we now gate on SMP) and both default to y.

---
 arch/sh/Kconfig    | 1 +
 arch/sh/mm/Kconfig | 9 ---------
 2 files changed, 1 insertion(+), 9 deletions(-)

index d5795067befaa..cf8437738a7bd 100644
@@ -13,6 +13,7 @@ config SUPERH
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_HIBERNATION_POSSIBLE if MMU
 	select ARCH_MIGHT_HAVE_PC_PARPORT
+	select ARCH_SUPPORTS_SCHED_MC if SMP
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select ARCH_NEED_CMPXCHG_1_EMU
 	select CPU_NO_EFFICIENT_FFS

index 1862411665ab8..e6762a0e46e59 100644
@@ -182,15 +182,6 @@ config HUGETLB_PAGE_SIZE_64MB
 
 endchoice
 
-config SCHED_MC
-	bool "Multi-core scheduler support"
-	depends on SMP
-	default y
-	help
-	  Multi-core scheduler support improves the CPU scheduler's decision
-	  making when dealing with multi-core CPU chips at a cost of slightly
-	  increased overhead in some places. If unsure say N here.
-
 endmenu
 
 menu "Cache configuration"

2.53.0