riscv: Remove unused _TIF_WORK_MASK

Since commit f0bddf50 ("riscv: entry: Convert to generic entry"),
_TIF_WORK_MASK is no longer used, so remove it.

Fixes: f0bddf50 ("riscv: entry: Convert to generic entry")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Andy Chiu <andy.chiu@sifive.com>
Link: https://lore.kernel.org/r/20240711111508.1373322-1-ruanjinjie@huawei.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

arch/riscv/include/asm/thread_info.h

@@ -112,8 +112,4 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
 #define _TIF_UPROBE		(1 << TIF_UPROBE)
 #define _TIF_RISCV_V_DEFER_RESTORE	(1 << TIF_RISCV_V_DEFER_RESTORE)
 
-#define _TIF_WORK_MASK \
-	(_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NEED_RESCHED | \
-	 _TIF_NOTIFY_SIGNAL | _TIF_UPROBE)
-
 #endif /* _ASM_RISCV_THREAD_INFO_H */