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/Makefile b/drivers/clk/Makefile
index 26bf429..dd97474 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -40,6 +40,7 @@
 obj-$(CONFIG_CLK_MVEBU) += mvebu/
 obj-$(CONFIG_CLK_OCTEON) += clk_octeon.o
 obj-$(CONFIG_CLK_OWL) += owl/
+obj-$(CONFIG_CLK_QCOM) += qcom/
 obj-$(CONFIG_CLK_RENESAS) += renesas/
 obj-$(CONFIG_$(SPL_TPL_)CLK_SCMI) += clk_scmi.o
 obj-$(CONFIG_CLK_SIFIVE) += sifive/