mtd: lpddr: Move function print_drs_error to lpddr_cmds.c

Function print_drs_error is only used in drivers/mtd/lpddr/lpddr_cmds.c
so, better to move it there.

Also, notice that there's no need for inline as the function is used
once.  Lastly, fix the following checkpatch warning:

WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
+static void print_drs_error(unsigned dsr)

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/e0063cbd65f3b47be1db34efc494ea3047634d88.1588016644.git.gustavo@embeddedor.com