RISC-V: QoS: expose implementation to resctrl

The generic resctrl header include/linux/resctrl.h includes
asm/resctrl.h when CONFIG_ARCH_HAS_CPU_RESCTRL is set.

Co-developed-by: Adrien Ricciardi <aricciardi@baylibre.com>
Signed-off-by: Adrien Ricciardi <aricciardi@baylibre.com>
Signed-off-by: Drew Fustini <dfustini@baylibre.com>

arch/riscv/include/asm/resctrl.h

+/* SPDX-License-Identifier: GPL-2.0-only */
+#include <linux/riscv_qos.h>