If the regulator_get_optional()	call for the SRAM regulator returns
a probe deferral, we must bail out and retry probing later: failing
to do this will	produce	unstabilities on platforms requiring the
handling for this regulator.

Fixes: b615b00c42da ("PM / devfreq: mediatek: Introduce MediaTek CCI devfreq driver")
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

We introduce a devfreq driver for the MediaTek Cache Coherent Interconnect
(CCI) used by some MediaTek SoCs.

In this driver, we use the passive devfreq driver to get target frequencies
and adjust voltages accordingly. In MT8183 and MT8186, the MediaTek CCI
is supplied by the same regulators with the little core CPUs.

Signed-off-by: Jia-Wei Chang <jia-wei.chang@mediatek.com>
Signed-off-by: Johnson Wang <johnson.wang@mediatek.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>