topology: fix uint32_t overflow in control decoder size checks

topology: fix uint32_t overflow in control decoder size checks

size2 = x->size + x->priv.size was computed in 32-bit arithmetic and could
wrap on a 64-bit host, bypassing the subsequent bounds check. Pre-check
for overflow then cast to size_t. Affects tplg_decode_control_mixer,
tplg_decode_control_enum, and tplg_decode_control_bytes.

Closes: https://github.com/alsa-project/alsa-lib/pull/527
Signed-off-by: Harsh Raj Singhania <raj.harshraut@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>