irqchip/riscv-intc: remove user selectability of RISCV_INTC

Since commit e71ee06e3c ("RISC-V: Force select RISCV_INTC for
CONFIG_RISCV") the driver has been enabled at the arch level - and is
mandatory anyway. There's no point exposing this as a choice to users,
so stop bothering.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221118104300.85016-3-conor@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

drivers/irqchip/Kconfig

@@ -538,17 +538,8 @@ config TI_PRUSS_INTC
 	  different processors within the SoC.
 
 config RISCV_INTC
-	bool "RISC-V Local Interrupt Controller"
+	bool
 	depends on RISCV
-	default y
-	help
-	   This enables support for the per-HART local interrupt controller
-	   found in standard RISC-V systems.  The per-HART local interrupt
-	   controller handles timer interrupts, software interrupts, and
-	   hardware interrupts. Without a per-HART local interrupt controller,
-	   a RISC-V system will be unable to handle any interrupts.
-
-	   If you don't know what to do here, say Y.
 
 config SIFIVE_PLIC
 	bool