clk: iproc: add initial common clock support

This adds basic and generic support for various iProc PLLs and clocks
including the ARMPLL, GENPLL, LCPLL, MIPIPLL, and ASIU clocks.

SoCs under the iProc architecture can define their specific register
offsets and clock parameters for their PLL and clock controllers. These
parameters can be passed as arugments into the generic iProc PLL and
clock setup functions

Derived from code originally provided by Jonathan Richardson
<jonathar@broadcom.com>

Signed-off-by: Ray Jui <rjui@broadcom.com>
Reviewed-by: Scott Branden <sbranden@broadcom.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>

drivers/clk/bcm/Kconfig

@@ -7,3 +7,12 @@ config CLK_BCM_KONA
 	  Enable common clock framework support for Broadcom SoCs
 	  using "Kona" style clock control units, including those
 	  in the BCM281xx and BCM21664 families.
+
+config COMMON_CLK_IPROC
+	bool "Broadcom iProc clock support"
+	depends on ARCH_BCM_IPROC
+	depends on COMMON_CLK
+	default ARCH_BCM_IPROC
+	help
+	  Enable common clock framework support for Broadcom SoCs
+	  based on the iProc architecture