{configure,avcodec/libx264}: remove separate x264_csp_bgr check

We already require X264_BUILD >= 118, which includes an unconditional
definition of X264_CSP_BGR in itself, thus making this check
effectively always true.

configure

@@ -3316,7 +3316,7 @@ libwebp_anim_encoder_deps="libwebp"
 libx262_encoder_deps="libx262"
 libx264_encoder_deps="libx264"
 libx264_encoder_select="atsc_a53"
-libx264rgb_encoder_deps="libx264 x264_csp_bgr"
+libx264rgb_encoder_deps="libx264"
 libx264rgb_encoder_select="libx264_encoder"
 libx265_encoder_deps="libx265"
 libxavs_encoder_deps="libxavs"
@@ -6529,7 +6529,6 @@ enabled libx264           && { check_pkg_config libx264 x264 "stdint.h x264.h" x
                                { require libx264 "stdint.h x264.h" x264_encoder_encode "-lx264 $pthreads_extralibs $libm_extralibs" &&
                                  warn "using libx264 without pkg-config"; } } &&
                              require_cpp_condition libx264 x264.h "X264_BUILD >= 118" &&
-                             check_cpp_condition x264_csp_bgr x264.h "X264_CSP_BGR" &&
                              check_cpp_condition libx262 x264.h "X264_MPEG2"
 enabled libx265           && require_pkg_config libx265 x265 x265.h x265_api_get &&
                              require_cpp_condition libx265 x265.h "X265_BUILD >= 70"

libavcodec/libx264.c

@@ -553,7 +553,6 @@ static int convert_pix_fmt(enum AVPixelFormat pix_fmt)
     case AV_PIX_FMT_YUVJ444P:
     case AV_PIX_FMT_YUV444P9:
     case AV_PIX_FMT_YUV444P10: return X264_CSP_I444;
-#if CONFIG_LIBX264RGB_ENCODER
     case AV_PIX_FMT_BGR0:
         return X264_CSP_BGRA;
     case AV_PIX_FMT_BGR24:
@@ -561,7 +560,6 @@ static int convert_pix_fmt(enum AVPixelFormat pix_fmt)
 
     case AV_PIX_FMT_RGB24:
         return X264_CSP_RGB;
-#endif
     case AV_PIX_FMT_NV12:      return X264_CSP_NV12;
     case AV_PIX_FMT_NV16:
     case AV_PIX_FMT_NV20:      return X264_CSP_NV16;