Separate implementations of AMAX and IAMAX on arm

As noted in #1912 and comment on #1942, the combined implementation happens to "do the right thing" on hardfp, but cannot return both value and index on softfp where they would have to share the return register

Author: martin-frbg

kernel/arm/KERNEL.ARMV6

@@ -1,20 +1,20 @@
 include $(KERNELDIR)/KERNEL.ARMV5
 
-SAMAXKERNEL  = iamax_vfp.S
-DAMAXKERNEL  = iamax_vfp.S
-CAMAXKERNEL  = iamax_vfp.S
-ZAMAXKERNEL  = iamax_vfp.S
+SAMAXKERNEL  = amax_vfp.S
+DAMAXKERNEL  = amax_vfp.S
+CAMAXKERNEL  = amax_vfp.S
+ZAMAXKERNEL  = amax_vfp.S
 
-SAMINKERNEL  = iamax_vfp.S
-DAMINKERNEL  = iamax_vfp.S
-CAMINKERNEL  = iamax_vfp.S
-ZAMINKERNEL  = iamax_vfp.S
+SAMINKERNEL  = amax_vfp.S
+DAMINKERNEL  = amax_vfp.S
+CAMINKERNEL  = amax_vfp.S
+ZAMINKERNEL  = amax_vfp.S
 
-SMAXKERNEL   = iamax_vfp.S
-DMAXKERNEL   = iamax_vfp.S
+SMAXKERNEL   = amax_vfp.S
+DMAXKERNEL   = amax_vfp.S
 
-SMINKERNEL   = iamax_vfp.S
-DMINKERNEL   = iamax_vfp.S
+SMINKERNEL   = amax_vfp.S
+DMINKERNEL   = amax_vfp.S
 
 ISAMAXKERNEL = iamax_vfp.S
 IDAMAXKERNEL = iamax_vfp.S