x86inc: Use .rdata instead of .rodata on Windows

The standard section for read-only data on Windows is .rdata. Nasm will
flag non-standard sections as executable by default which isn't ideal.

libavutil/x86/x86inc.asm

@@ -90,6 +90,10 @@
         SECTION .text
     %elifidn __OUTPUT_FORMAT__,coff
         SECTION .text
+    %elifidn __OUTPUT_FORMAT__,win32
+        SECTION .rdata align=%1
+    %elif WIN64
+        SECTION .rdata align=%1
     %else
         SECTION .rodata align=%1
     %endif