RISC-V: stop selecting SIFIVE_PLIC at the SoC level

The SIFIVE_PLIC driver is used by all current RISC-V SoCs & will be,
where possible, used for future implementations. Rather than having each
driver select the option on a case-by-case basis, do so at the arch
level.
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221118104300.85016-4-conor@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

arch/riscv/Kconfig

@@ -123,6 +123,7 @@ config RISCV
 	select PCI_MSI if PCI
 	select RISCV_INTC
 	select RISCV_TIMER if RISCV_SBI
+	select SIFIVE_PLIC
 	select SPARSE_IRQ
 	select SYSCTL_EXCEPTION_TRACE
 	select THREAD_INFO_IN_TASK

arch/riscv/Kconfig.socs

@@ -3,7 +3,6 @@ menu "SoC selection"
 config SOC_MICROCHIP_POLARFIRE
 	bool "Microchip PolarFire SoCs"
 	select MCHP_CLK_MPFS
-	select SIFIVE_PLIC
 	help
 	  This enables support for Microchip PolarFire SoC platforms.
 
@@ -13,7 +12,6 @@ config SOC_SIFIVE
 	select SERIAL_SIFIVE_CONSOLE if TTY
 	select CLK_SIFIVE
 	select CLK_SIFIVE_PRCI
-	select SIFIVE_PLIC
 	select ERRATA_SIFIVE if !XIP_KERNEL
 	help
 	  This enables support for SiFive SoC platform hardware.
@@ -22,7 +20,6 @@ config SOC_STARFIVE
 	bool "StarFive SoCs"
 	select PINCTRL
 	select RESET_CONTROLLER
-	select SIFIVE_PLIC
 	help
 	  This enables support for StarFive SoC platform hardware.
 
@@ -34,7 +31,6 @@ config SOC_VIRT
 	select POWER_RESET_SYSCON_POWEROFF
 	select GOLDFISH
 	select RTC_DRV_GOLDFISH if RTC_CLASS
-	select SIFIVE_PLIC
 	select PM_GENERIC_DOMAINS if PM
 	select PM_GENERIC_DOMAINS_OF if PM && OF
 	select RISCV_SBI_CPUIDLE if CPU_IDLE && RISCV_SBI
@@ -47,7 +43,6 @@ config SOC_CANAAN
 	select CLINT_TIMER if RISCV_M_MODE
 	select SERIAL_SIFIVE if TTY
 	select SERIAL_SIFIVE_CONSOLE if TTY
-	select SIFIVE_PLIC
 	select ARCH_HAS_RESET_CONTROLLER
 	select PINCTRL
 	select COMMON_CLK