LoongArch: Disable executable stack by default

Disable executable stack for LoongArch by default, as all modern
architectures do.
Reported-by: Andreas Schwab <schwab@suse.de>
Suggested-by: WANG Xuerui <git@xen0n.name>
Link: https://sourceware.org/pipermail/binutils/2022-July/121992.htmlTested-by: WANG Xuerui <git@xen0n.name>
Tested-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

arch/loongarch/include/asm/elf.h

@@ -288,8 +288,6 @@ struct arch_elf_state {
 	.interp_fp_abi = LOONGARCH_ABI_FP_ANY,	\
 }
 
-#define elf_read_implies_exec(ex, exec_stk) (exec_stk == EXSTACK_DEFAULT)
-
 extern int arch_elf_pt_proc(void *ehdr, void *phdr, struct file *elf,
 			    bool is_interp, struct arch_elf_state *state);