configure: arm: set fast_clz and fast_unaligned in cpuflags section

These are properties of the targeted core and do not depend on
specific assembly support in the toolchain which if missing will
render the controlling options here disabled.
Signed-off-by: Mans Rullgard <mans@mansr.com>

configure

@@ -1419,8 +1419,8 @@ done
 
 aligned_stack_if_any="ppc x86"
 fast_64bit_if_any="alpha ia64 mips64 parisc64 ppc64 sparc64 x86_64"
-fast_clz_if_any="alpha armv5te avr32 mips ppc x86"
-fast_unaligned_if_any="armv6 ppc x86"
+fast_clz_if_any="alpha avr32 mips ppc x86"
+fast_unaligned_if_any="ppc x86"
 
 inline_asm_deps="!tms470"
 need_memalign="altivec neon sse"
@@ -2591,6 +2591,11 @@ elif enabled arm; then
         ;;
     esac
 
+    case "$subarch" in
+        armv5t*)    enable fast_clz                ;;
+        armv[6-8]*) enable fast_clz fast_unaligned ;;
+    esac
+
 elif enabled avr32; then
 
     case $cpu in