ALSA: fireworks: use u32 type for be32_to_cpup() macro

In former commit, snd_efw_command_get_phys_meters() was added to handle
metering data. The given buffer is used to save transaction result and to
convert between endianness. But this causes sparse warnings.

fireworks_command.c:269:25: warning: incorrect type in argument 1 (different base types)
fireworks_command.c:269:25:    expected unsigned int [usertype] *p
fireworks_command.c:269:25:    got restricted __be32 [usertype] *

This commit fixes this bug.

Fixes: bde8a8f2('ALSA: fireworks: Add transaction and some commands')
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>