ARM: Don't unconditionally bloat thread_info

There is no point reserving space at the bottom of the kernel stack for
per-thread crunch state, and per-thread VFP state if these are not being
supported by the kernel being built.  Remove these members from the
thread union when these features are disabled.
Reported-by: NTim Bird <tim.bird@am.sony.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/include/asm/thread_info.h

@@ -59,7 +59,9 @@ struct thread_info {
 	__u32			syscall;	/* syscall number */
 	__u8			used_cp[16];	/* thread used copro */
 	unsigned long		tp_value;
+#ifdef CONFIG_CRUNCH
 	struct crunch_state	crunchstate;
+#endif
 	union fp_state		fpstate __attribute__((aligned(8)));
 	union vfp_state		vfpstate;
 #ifdef CONFIG_ARM_THUMBEE

arch/arm/kernel/asm-offsets.c

@@ -59,10 +59,12 @@ int main(void)
   DEFINE(TI_USED_CP,		offsetof(struct thread_info, used_cp));
   DEFINE(TI_TP_VALUE,		offsetof(struct thread_info, tp_value));
   DEFINE(TI_FPSTATE,		offsetof(struct thread_info, fpstate));
+#ifdef CONFIG_VFP
   DEFINE(TI_VFPSTATE,		offsetof(struct thread_info, vfpstate));
 #ifdef CONFIG_SMP
   DEFINE(VFP_CPU,		offsetof(union vfp_state, hard.cpu));
 #endif
+#endif
 #ifdef CONFIG_ARM_THUMBEE
   DEFINE(TI_THUMBEE_STATE,	offsetof(struct thread_info, thumbee_state));
 #endif