platform: generic: thead: separate implement of T-HEAD c9xx errata

Separate the implement of T-HEAD c9xx errata to allow any platform
with bug related to c9xx cores can use it.

Signed-off-by: Inochi Amaoto <inochiama@outlook.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

platform/generic/include/thead/c9xx_errata.h

@@ -0,0 +1,13 @@
+
+#ifndef __RISCV_THEAD_C9XX_ERRATA_H____
+#define __RISCV_THEAD_C9XX_ERRATA_H____
+
+/**
+ * T-HEAD board with this quirk need to execute sfence.vma to flush
+ * stale entrie avoid incorrect memory access.
+ */
+#define THEAD_QUIRK_ERRATA_TLB_FLUSH		BIT(0)
+
+void thead_register_tlb_flush_trap_handler(void);
+
+#endif // __RISCV_THEAD_C9XX_ERRATA_H____