clk: bcm: Fix unmet Kconfig dependencies for CLK_BCM_63XX

With commit f4e87150 ("clk: iproc: Make clocks visible options"),
COMMON_CLK_IPROC gained a dependency on ARCH_BCM_IPROC, yet CLK_BCM_63XX
also selects that option, this causes the following Kconfig warning:

warning: (CLK_BCM_63XX) selects COMMON_CLK_IPROC which has unmet direct
dependencies ((ARCH_BCM_IPROC || COMPILE_TEST) && COMMON_CLK)

Fix this by adding proper depends for COMMON_CLK_IPROC

Fixes: f4e87150 ("clk: iproc: Make clocks visible options")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Ray Jui <ray.jui@broadcom.com>
[sboyd@codeaurora.org: Drop default part as it's redundant]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>