allow compiling ffmpeg on non x86 platforms

The assembly instruction emms is only available on the x86 platform and given
the existing __SSE_MATH__ check it is not required when the compiler is using
sse for floating point math.  Add a check to only enable when not using
__SSE_MATH__ and when mmx is available with __pentium_mmx__ In my case the
instruction doesn't compile on arm.

Author: dfries

CHANGELOG

@@ -85,6 +85,7 @@ Bugfixes
    * Fixed leak in vloopback.
    * Fixed a build of motion for some kernel version with not good videodev.h 
    * Fix webhttpd race condition crash with SIGHUP, add it to running thread counter (David Fries)
+   * Limit asm emms call to allow compiling on non x86 (ARM) systems (David Fries)
 
 3.2.12 Summary of Changes
 

CREDITS

@@ -477,6 +477,7 @@ David Fries
    * Fix webhttpd race condition crash with SIGHUP, add it to running thread counter
    * Allow text format specifiers to take a width like printf would.
    * Add power_line_frequency configuration item to improve image quality.
+   * Limit asm emms call to allow compiling on non x86 (ARM) systems
 
 Aaron Gage
    * Pointed me to the vid_mmap/int problem when calling SYNC in

ffmpeg.c

@@ -1000,7 +1000,8 @@ void ffmpeg_deinterlace(unsigned char *img, int width, int height)
     /* We assume using 'PIX_FMT_YUV420P' always */
     avpicture_deinterlace(&picture, &picture, PIX_FMT_YUV420P, width, height);
 
-#ifndef __SSE_MATH__
+#if !defined(__SSE_MATH__) && defined(__pentium_mmx__)
+    /* re-allow floating point operations, x86-32 only */
     __asm__ __volatile__ ( "emms");
 #endif