swscale/x86/ops: add section comments (cosmetic)

Sponsored-by: Sovereign Tech Fund
Signed-off-by: Niklas Haas <git@haasn.dev>

libswscale/x86/ops_float.asm

@@ -130,6 +130,9 @@ IF W,   vpermq mw, mw, q3120
         CONTINUE tmp0q
 %endmacro
 
+;---------------------------------------------------------
+; Arithmetic operations
+
 %macro min_max 0
 op min
 IF X,   vbroadcastss m8,  [implq + SwsOpImpl.priv + 0]
@@ -179,6 +182,9 @@ IF W,   mulps mw2, m8
         CONTINUE tmp0q
 %endmacro
 
+;---------------------------------------------------------
+; Dithering
+
 %macro dither0 0
 op dither0
         ; constant offset for all channels
@@ -253,6 +259,9 @@ op dither%1
         dither 8
 %endmacro
 
+;---------------------------------------------------------
+; Linear transformations
+
 %xdefine MASK(I, J)  (1 << (5 * (I) + (J)))
 %xdefine MASK_OFF(I) MASK(I, 4)
 %xdefine MASK_ROW(I) (0x1F << (5 * (I)))