The consumer drivers can make use of the pwrseq device's 'dev' pointer to
query the pwrseq provider's DT node to check for existence of specific
properties.

Hence, add an API to return the pwrseq device's 'dev' pointer to consumers.

Note that since pwrseq_get() would've increased the pwrseq refcount, there
is no need to increase the refcount in this API again.

Tested-by: Wei Deng <wei.deng@oss.qualcomm.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Link: https://patch.msgid.link/20260519-pwrseq-m2-bt-v3-6-b39dc2ae3966@oss.qualcomm.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

Implement the power sequencing subsystem allowing devices to share
complex powering-up and down procedures. It's split into the consumer
and provider parts but does not implement any new DT bindings so that
the actual power sequencing is never revealed in the DT representation.

Tested-by: Amit Pundir <amit.pundir@linaro.org>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-QRD, SM8650-QRD & SM8650-HDK
Tested-by: Caleb Connolly <caleb.connolly@linaro.org> # OnePlus 8T
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20240605123850.24857-2-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>