arm64: efi: Remove CONFIG_VMAP_STACK check

Remove the CONFIG_VMAP_STACK check in arm64_efi_rt_init() since
VMAP_STACK is now always enabled on arm64.

The arch_alloc_vmap_stack() call will fail to build if VMAP_STACK
is not set, providing sufficient protection without the explicit
runtime check.

Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707-arm64_vmap-v1-2-8de98ca0f91c@debian.org
Signed-off-by: Will Deacon <will@kernel.org>

Author: leitao

arch/arm64/kernel/efi.c

@@ -215,11 +215,6 @@ static int __init arm64_efi_rt_init(void)
 	if (!efi_enabled(EFI_RUNTIME_SERVICES))
 		return 0;
 
-	if (!IS_ENABLED(CONFIG_VMAP_STACK)) {
-		clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
-		return -ENOMEM;
-	}
-
 	p = arch_alloc_vmap_stack(THREAD_SIZE, NUMA_NO_NODE);
 	if (!p) {
 		pr_warn("Failed to allocate EFI runtime stack\n");