bcma: print chip ID in a more user-friendly form

Some chip IDs are easier to read/understand when printed in a decimal
form. For example on my bcm53xx arch router this patch replaces:
Found chip with id 0xCF12, rev 0x00 and package 0x02
with a:
Found chip with id 53010, rev 0x00 and package 0x02

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>