ASoC: fsl-asoc-card: use integer type for fll_id and pll_id

As the pll_id and pll_id can be zero (WM8960_SYSCLK_AUTO)
with the commit 2bbc2df4 ("ASoC: wm8960: Make automatic the
default clocking mode")

Then the machine driver will skip to call set_sysclk() and set_pll()
for codec, when the sysclk rate is different with what wm8960 read
at probe, the output sound frequency is wrong.

So change the fll_id and pll_id initial value, still keep machine
driver's behavior same as before.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Link: https://lore.kernel.org/r/1695202992-24864-1-git-send-email-shengjiu.wang@nxp.com


Signed-off-by: Mark Brown <broonie@kernel.org>