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/MAINTAINERS b/MAINTAINERS
index 4fec063..185f5eb 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -575,6 +575,7 @@
 R:	Sumit Garg <sumit.garg@linaro.org>
 S:	Maintained
 F:	arch/arm/mach-snapdragon/
+F:	drivers/clk/qcom/
 F:	drivers/gpio/msm_gpio.c
 F:	drivers/mmc/msm_sdhci.c
 F:	drivers/phy/msm8916-usbh-phy.c