ALSA: sb16 - Fix build errors on MIPS and others with 13bit ioctl size

One of ioctl definition in sound/sb16_csp.h contains the data size
over 8kB, and this causes build errors on architectures like MIPS,
which define _IOC_SIZEBITS=13.

For avoiding this build errors but keeping the compatibility, manually
expand with _IOC() instead of using _IOW() for the problematic ioctl.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

include/sound/sb16_csp.h

@@ -99,7 +99,14 @@ struct snd_sb_csp_info {
 /* get CSP information */
 #define SNDRV_SB_CSP_IOCTL_INFO		_IOR('H', 0x10, struct snd_sb_csp_info)
 /* load microcode to CSP */
-#define SNDRV_SB_CSP_IOCTL_LOAD_CODE	_IOW('H', 0x11, struct snd_sb_csp_microcode)
+/* NOTE: struct snd_sb_csp_microcode overflows the max size (13 bits)
+ * defined for some architectures like MIPS, and it leads to build errors.
+ * (x86 and co have 14-bit size, thus it's valid, though.)
+ * As a workaround for skipping the size-limit check, here we don't use the
+ * normal _IOW() macro but _IOC() with the manual argument.
+ */
+#define SNDRV_SB_CSP_IOCTL_LOAD_CODE	\
+	_IOC(_IOC_WRITE, 'H', 0x11, sizeof(struct snd_sb_csp_microcode))
 /* unload microcode from CSP */
 #define SNDRV_SB_CSP_IOCTL_UNLOAD_CODE	_IO('H', 0x12)
 /* start CSP */