power: sequencing: make the QCom PMU pwrseq driver depend on CONFIG_OF

This driver uses various OF-specific functions and depends on phandle
parsing. There's no reason to make it available to non-OF systems so add
a relevant dependency switch to its Kconfig entry.

Fixes: 2f1630f4 ("power: pwrseq: add a driver for the PMU module on the QCom WCN chipsets")
Link: https://lore.kernel.org/r/20241004130449.51725-1-brgl@bgdev.pl


Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>