rockchip: rk3399: spl: always report errors triggering a hard stop

rockchip: rk3399: spl: always report errors triggering a hard stop

The RK3399 SPL has two cases that may end in a hard-stop: if either
the pinctrl can not be initialised or if the DRAM fails to initialise.
Both have previously not triggered an error message unless DEBUG was
defined (i.e. both used debug() to print the error).

This converts both error messages to be printed using pr_err() to
ensure that some output points to the cause of the hard-stop.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>