[ARM] pxafb: Remove #if DEBUG, convert DPRINTK to pr_debug

Fix warning:
 drivers/video/pxafb.h:119:5: warning: "DEBUG" is not defined
by removing the whole
 #if DEBUG
 #define DPRINTK(fmt, args...) printk...etc...
 #else
 #define DPRINTK(fmt, args...)
 #endif
stuff - we have pr_debug() for this.

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