ARM: clcd: clean up CLCD announcement printks

Make the CLCD announcement printk say which primecell part number
has been found.  Display the revision as an unsigned decimal, and
display only the first 8 hex digits of the base address unless it's
larger.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>