ARM: dts: Fix audio card detection on Peach boards

Since commit 2fad972d ("ARM: dts: Add mclk entry for Peach boards"),
sound card detection is broken on peach boards and gives below errors:

[    3.630457] max98090 7-0010: MAX98091 REVID=0x51
[    3.634233] max98090 7-0010: use default 2.8v micbias
[    3.640985] snow-audio sound: HiFi <-> 3830000.i2s mapping ok
[    3.645307] max98090 7-0010: Invalid master clock frequency
[    3.650824] snow-audio sound: ASoC: Peach-Pi-I2S-MAX98091 late_probe() failed: -22
[    3.658914] snow-audio sound: snd_soc_register_card failed (-22)
[    3.664366] snow-audio: probe of sound failed with error -22

This patch adds missing assigned-clocks and assigned-clock-parents for
pmu_system_controller node which is used as "mclk" for audio codec.

Fixes: 2fad972d

 ("ARM: dts: Add mclk entry for Peach boards")
Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Kukjin Kim <kgene@kernel.org>