arm64: sve: Provide sve_cond_update_zcr_vq fallback when !ARM64_SVE

mainline inclusion
from mainline-v5.13-rc1~76^2
commit a9f8696d
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5ITJT
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a9f8696d4be5228de9d1d4f0e9f027b64d77dab6

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

Compilation fails when KVM is selected and ARM64_SVE isn't.

The root cause is that sve_cond_update_zcr_vq is not defined when
ARM64_SVE is not selected. Fix it by adding an empty definition
when CONFIG_ARM64_SVE=n.
Signed-off-by: NXiaofei Tan <tanxiaofei@huawei.com>
[maz: simplified commit message, fleshed out dummy #define]
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1617183879-48748-1-git-send-email-tanxiaofei@huawei.comSigned-off-by: NWang ShaoBo <bobo.shaobowang@huawei.com>

arch/arm64/include/asm/fpsimd.h

@@ -167,6 +167,8 @@ static inline int sve_get_current_vl(void)
 static inline void sve_user_disable(void) { BUILD_BUG(); }
 static inline void sve_user_enable(void) { BUILD_BUG(); }
 
+#define sve_cond_update_zcr_vq(val, reg) do { } while (0)
+
 static inline void sve_init_vq_map(void) { }
 static inline void sve_update_vq_map(void) { }
 static inline int sve_verify_vq_map(void) { return 0; }