ARM: mvebu: add missing newline at end of messages

Commit 548ae94c ("ARM: mvebu: Disable CPU Idle on Armada 38x")
added two new pr_warn() messages in mach-mvebu/pmsu.c. However, these
messages lack the final new line, causing the next message to be
displayed on the same line.

This commit adds the missing ending newlines.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>