riscv: allow usage of ACPI

Select CONFIG_SUPPORT_ACPI to allow usage of ACPI tables with RISC-V.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/Kconfig

@@ -108,6 +108,7 @@ config PPC
 config RISCV
 	bool "RISC-V architecture"
 	select CREATE_ARCH_SYMLINK
+	select SUPPORT_ACPI
 	select SUPPORT_OF_CONTROL
 	select OF_CONTROL
 	select DM