linux-phytec-fsl

ASoC: rt5640: Rename the function of clock checking

In order to identify clearly, the patch renames the function
"check_sysclk1_source" to "is_sys_clk_from_pll".

Signed-off-by: Oder Chiou <oder_chiou@realtek.com>
Signed-off-by: Mark Brown <broonie@linaro.org>