x86/entry/64: Don't compile ignore_sysret if 32-bit emulation is enabled

mainline inclusion
from mainline-v5.3
commit dffb3f9d
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5Q0UG?from=project-issue


CVE: NA

---------------------------

It's only used if !CONFIG_IA32_EMULATION, so disable it in normal
configs.  This will save a few bytes of text and reduce confusion.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc:  "BaeChang Seok" <chang.seok.bae@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Bae, Chang Seok" <chang.seok.bae@intel.com>
Link: https://lkml.kernel.org/r/0f7dafa72fe7194689de5ee8cfe5d83509fabcf5.1562035429.git.luto@kernel.org



Signed-off-by: tangbin <tangbin_yewu@cmss.chinamobile.com>