ARM: dts: broadcom: Fix SP804 node

The DT binding for SP804 requires to have an "arm,primecell" compatible
string.
Add this string so that the Linux primecell bus driver picks the device
up and activates the clock.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
[florian: added compatible to ccbtimer1]
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>