arm64/sve: Make sve_state_size() static

There are no users outside fpsimd.c so make sve_state_size() static.
KVM open codes an equivalent.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-4-broonie@kernel.orgSigned-off-by: Will Deacon <will@kernel.org>

arch/arm64/include/asm/fpsimd.h

@@ -104,8 +104,6 @@ static inline bool sve_vq_available(unsigned int vq)
 
 #ifdef CONFIG_ARM64_SVE
 
-extern size_t sve_state_size(struct task_struct const *task);
-
 extern void sve_alloc(struct task_struct *task);
 extern void fpsimd_release_task(struct task_struct *task);
 extern void fpsimd_sync_to_sve(struct task_struct *task);

arch/arm64/kernel/fpsimd.c

@@ -497,7 +497,7 @@ static void sve_to_fpsimd(struct task_struct *task)
  * Return how many bytes of memory are required to store the full SVE
  * state for task, given task's currently configured vector length.
  */
-size_t sve_state_size(struct task_struct const *task)
+static size_t sve_state_size(struct task_struct const *task)
 {
 	return SVE_SIG_REGS_SIZE(sve_vq_from_vl(task->thread.sve_vl));
 }