arm64: entry: Switch to generic IRQ entry

arm64: entry: Switch to generic IRQ entry

Currently, x86, Riscv and Loongarch use the generic entry code, which
makes maintainer's work easier and code more elegant. Start converting
arm64 to use the generic entry infrastructure from kernel/entry/* by
switching it to generic IRQ entry, which removes 100+ lines of duplicate
code. arm64 will completely switch to generic entry in a later series.

The changes are below:
 - Remove *enter_from/exit_to_kernel_mode(), and wrap with generic
   irqentry_enter/exit() as their code and functionality are almost
   identical.

 - Define ARCH_EXIT_TO_USER_MODE_WORK and implement
   arch_exit_to_user_mode_work() to check arm64-specific thread flags
   "_TIF_MTE_ASYNC_FAULT" and "_TIF_FOREIGN_FPSTATE".
   So also remove *enter_from/exit_to_user_mode(), and wrap with
   generic enter_from/exit_to_user_mode() because they are
   exactly the same.

 - Remove arm64_enter/exit_nmi() and use generic irqentry_nmi_enter/exit()
   because they're exactly the same, so the temporary arm64 version
   irqentry_state can also be removed.

 - Remove PREEMPT_DYNAMIC code, as generic irqentry_exit_cond_resched()
   has the same functionality.

 - Implement arch_irqentry_exit_need_resched() with
   arm64_preempt_schedule_irq() for arm64 which will allow arm64 to do
   its architecture specific checks.

Tested-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Suggested-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>