powerpc/8xx: Remove 8xx specific "minimal FPU emulation"

This is duplicated code from math-emu and implements such a small
subset of the FPU (load/stores/fmr) that it's essentially pointless
nowdays.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/Kconfig

@@ -319,17 +319,6 @@ config PPC_TRANSACTIONAL_MEM
        ---help---
          Support user-mode Transactional Memory on POWERPC.
 
-config 8XX_MINIMAL_FPEMU
-	bool "Minimal math emulation for 8xx"
-	depends on 8xx && !MATH_EMULATION
-	help
-	  Older arch/ppc kernels still emulated a few floating point
-	  instructions such as load and store, even when full math
-	  emulation is disabled.  Say "Y" here if you want to preserve
-	  this behavior.
-
-	  It is recommended that you build a soft-float userspace instead.
-
 config IOMMU_HELPER
 	def_bool PPC64
 

arch/powerpc/kernel/traps.c

@@ -1396,8 +1396,7 @@ void performance_monitor_exception(struct pt_regs *regs)
 void SoftwareEmulation(struct pt_regs *regs)
 {
 	extern int do_mathemu(struct pt_regs *);
-	extern int Soft_emulate_8xx(struct pt_regs *);
-#if defined(CONFIG_MATH_EMULATION) || defined(CONFIG_8XX_MINIMAL_FPEMU)
+#if defined(CONFIG_MATH_EMULATION)
 	int errcode;
 #endif
 
@@ -1430,23 +1429,6 @@ void SoftwareEmulation(struct pt_regs *regs)
 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
 		return;
 	}
-
-#elif defined(CONFIG_8XX_MINIMAL_FPEMU)
-	errcode = Soft_emulate_8xx(regs);
-	if (errcode >= 0)
-		PPC_WARN_EMULATED(8xx, regs);
-
-	switch (errcode) {
-	case 0:
-		emulate_single_step(regs);
-		return;
-	case 1:
-		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
-		return;
-	case -EFAULT:
-		_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
-		return;
-	}
 #else
 	_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
 #endif
@@ -1796,8 +1778,6 @@ struct ppc_emulated ppc_emulated = {
 	WARN_EMULATED_SETUP(unaligned),
 #ifdef CONFIG_MATH_EMULATION
 	WARN_EMULATED_SETUP(math),
-#elif defined(CONFIG_8XX_MINIMAL_FPEMU)
-	WARN_EMULATED_SETUP(8xx),
 #endif
 #ifdef CONFIG_VSX
 	WARN_EMULATED_SETUP(vsx),