avcodec/mips: Fix checkheaders

mips has several headers that are only meant for inclusion in another
non-arch specific file; they do not even try to be standalone. So don't
test them in checkheaders.

Also fix vp9dsp_mips.h, an ordinary header missing some includes.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavcodec/mips/Makefile

@@ -1,3 +1,7 @@
+ARCH_HEADERS                               = aacsbr_mips.h aacpsy_mips.h   \
+                                             cabac.h compute_antialias_fixed.h \
+                                             compute_antialias_float.h     \
+
 MIPSFPU-OBJS-$(CONFIG_AMRNB_DECODER)      += mips/acelp_filters_mips.o     \
                                              mips/celp_filters_mips.o      \
                                              mips/celp_math_mips.o         \

libavcodec/mips/lsp_mips.h

@@ -54,6 +54,8 @@
 #ifndef AVCODEC_MIPS_LSP_MIPS_H
 #define AVCODEC_MIPS_LSP_MIPS_H
 
+#include "config.h"
+
 #if HAVE_MIPSFPU && HAVE_INLINE_ASM
 #if !HAVE_MIPS32R6 && !HAVE_MIPS64R6
 #include "libavutil/attributes.h"

libavcodec/mips/vp9dsp_mips.h

@@ -21,6 +21,9 @@
 #ifndef AVCODEC_MIPS_VP9DSP_MIPS_H
 #define AVCODEC_MIPS_VP9DSP_MIPS_H
 
+#include <stddef.h>
+#include <stdint.h>
+
 #define VP9_8TAP_MIPS_MSA_FUNC(SIZE, type, type_idx)                         \
 void ff_put_8tap_##type##_##SIZE##h_msa(uint8_t *dst, ptrdiff_t dststride,   \
                                         const uint8_t *src,                  \