clk/qcom: move from mach-snapdragon

Clock drivers don't belong here, move them to the right place and
declutter mach-snapdragon a bit.

To de-couple these drivers from specific "target" platforms, add
additional config options to enable each clock driver gated behind a
common CLK_QCOM option and enable them by default for the respective
targets. This will make future work easier as we move towards a generic
Qualcomm target.

Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index bfd23a9..017dd26 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -254,6 +254,7 @@
 source "drivers/clk/microchip/Kconfig"
 source "drivers/clk/mvebu/Kconfig"
 source "drivers/clk/owl/Kconfig"
+source "drivers/clk/qcom/Kconfig"
 source "drivers/clk/renesas/Kconfig"
 source "drivers/clk/sunxi/Kconfig"
 source "drivers/clk/sifive/Kconfig"