soc: xilinx: cleanup debug and error messages

Use dev_err/dev_dbg instead of pr_err/pr_debug.

Add the PM node ids to supplement the (arbitrary) power domain names to
include information which PM nodes are requested by the driver.

Drop function names from the messages, because they can easily be added
with dynamic debug.

Remove comments explaining that error messages are printed on errors.

Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Rajan Vaja <rajan.vaja@xilinx.com>
Link: https://lore.kernel.org/r/20210825150313.4033156-3-m.tretter@pengutronix.de


Signed-off-by: Michal Simek <michal.simek@xilinx.com>