ARM: omap: fix vc.c PMIC error message

While testing on my OMAP3430 platform, this error message was emitted:

omap_vc_init_channel: PMIC info requried to configure vc forvdd_core not populated.Hence cannot initialize vc

Trying to find this message was difficult because it was wrapped across
several lines.  It also mis-spells "required", doesn't read very well,
and has spaces lacking.  Let's replace it with a more concise:

omap_vc_init_channel: No PMIC info for vdd_core

While we're here, fix a simple spelling error in a comment.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>