ARM: remove check for PLD instruction

PLD is present in ARMv5TE and later, which is checked for separately.
Signed-off-by: Mans Rullgard <mans@mansr.com>

configure

@@ -1093,7 +1093,6 @@ HAVE_LIST="
     memalign
     mkstemp
     mmap
-    pld
     posix_memalign
     round
     roundf
@@ -2608,9 +2607,6 @@ EOF
         warn "Compiler does not indicate floating-point ABI, guessing $fpabi."
     fi
 
-    # We have to check if pld is a nop and disable it.
-    check_asm pld '"pld [r0]"'
-
     enabled armv5te && check_asm armv5te '"qadd r0, r0, r0"'
     enabled armv6   && check_asm armv6   '"sadd16 r0, r0, r0"'
     enabled armv6t2 && check_asm armv6t2 '"movt r0, #0"'

libavcodec/arm/dsputil_arm.S

@@ -24,11 +24,6 @@
 
         preserve8
 
-#if !HAVE_PLD
-.macro pld reg
-.endm
-#endif
-
 #if HAVE_ARMV5TE
 function ff_prefetch_arm, export=1
         subs            r2,  r2,  #1
@@ -37,6 +32,8 @@ function ff_prefetch_arm, export=1
         bne             ff_prefetch_arm
         bx              lr
 endfunc
+#else
+#define pld @
 #endif
 
 .macro  ALIGN_QWORD_D shift, Rd0, Rd1, Rd2, Rd3, Rn0, Rn1, Rn2, Rn3, Rn4