powerpc: Remove empty giveup_altivec function on book3e CPUs

Use an empty inline instead of an empty function to implement
giveup_altivec on book3e CPUs, similar to flush_altivec_to_thread.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/include/asm/switch_to.h

@@ -21,7 +21,6 @@ extern void disable_kernel_fp(void);
 extern void enable_kernel_fp(void);
 extern void flush_fp_to_thread(struct task_struct *);
 extern void enable_kernel_altivec(void);
-extern void giveup_altivec(struct task_struct *);
 extern void load_up_altivec(struct task_struct *);
 extern int emulate_altivec(struct pt_regs *);
 extern void __giveup_vsx(struct task_struct *);
@@ -40,10 +39,14 @@ static inline void discard_lazy_cpu_state(void)
 
 #ifdef CONFIG_ALTIVEC
 extern void flush_altivec_to_thread(struct task_struct *);
+extern void giveup_altivec(struct task_struct *);
 #else
 static inline void flush_altivec_to_thread(struct task_struct *t)
 {
 }
+static inline void giveup_altivec(struct task_struct *t)
+{
+}
 #endif
 
 #ifdef CONFIG_VSX

arch/powerpc/kernel/head_44x.S

@@ -777,14 +777,6 @@ _GLOBAL(__fixup_440A_mcheck)
 	sync
 	blr
 
-/*
- * extern void giveup_altivec(struct task_struct *prev)
- *
- * The 44x core does not have an AltiVec unit.
- */
-_GLOBAL(giveup_altivec)
-	blr
-
 /*
  * extern void giveup_fpu(struct task_struct *prev)
  *

arch/powerpc/kernel/head_fsl_booke.S

@@ -874,14 +874,6 @@ _GLOBAL(__setup_e500mc_ivors)
 	sync
 	blr
 
-/*
- * extern void giveup_altivec(struct task_struct *prev)
- *
- * The e500 core does not have an AltiVec unit.
- */
-_GLOBAL(giveup_altivec)
-	blr
-
 #ifdef CONFIG_SPE
 /*
  * extern void giveup_spe(struct task_struct *prev)