Instead of recursively calling rz_ssi_pio_recv() use a while loop
to read the samples from RX fifo.

This also fixes an issue where the return value of rz_ssi_pio_recv()
was ignored when called recursively.

Fixes: 03e786bd ("ASoC: sh: Add RZ/G2L SSIF-2 driver")
Reported-by: Pavel Machek <pavel@denx.de>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20220110094711.8574-2-prabhakar.mahadev-lad.rj@bp.renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>