RISC-V: Force select RISCV_INTC for CONFIG_RISCV

The RISC-V per-HART local interrupt controller driver is mandatory
for all RISC-V system (with/without MMU) hence we force select it
for CONFIG_RISCV (just like RISCV_TIMER).

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 4f5bff0..7c96149 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -66,6 +66,7 @@
 	select OF_IRQ
 	select PCI_DOMAINS_GENERIC if PCI
 	select PCI_MSI if PCI
+	select RISCV_INTC
 	select RISCV_TIMER
 	select SPARSEMEM_STATIC if 32BIT
 	select SPARSE_IRQ