clk: ti: omap5: Add missing gpmc and ocmc clkctrl

The gpmc clock is needed to update omap5 to boot with genpd with the
related devicetree patches. The ocmc clock is currently not used but
let's add it so we have all the clocks for the l3main2 defined.

Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Tero Kristo <kristo@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>