Revert "clk: bcm2835: remove pllb"

This reverts commit 2256d893. Since we
will be expanding the firmware clock driver, we'll need to remove the
quirks to deal with the PLLB. However, we still want to expose the clock
tree properly, so having that clock in the MMIO driver will allow that.

Acked-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/5d26a4c58248f5be7760a7f2f720a1310baea5dd.1592210452.git-series.maxime@cerno.tech


Signed-off-by: Stephen Boyd <sboyd@kernel.org>