clk: lpc18xx: add NXP specific COMMON_CLK_NXP configuration symbol

The change adds COMMON_CLK_NXP configuration symbol and enables it for
NXP LPC18XX architecture, this is needed to reuse drivers/clk/nxp
folder for NXP common clock framework drivers other than LPC18XX one.
Signed-off-by: NVladimir Zapolskiy <vz@mleia.com>
Acked-by: NJoachim Eastwood <manabian@gmail.com>
Signed-off-by: NMichael Turquette <mturquette@baylibre.com>

drivers/clk/Kconfig

@@ -175,6 +175,11 @@ config COMMON_CLK_PWM
 	  Adapter driver so that any PWM output can be (mis)used as clock signal
 	  at 50% duty cycle.
 
+config COMMON_CLK_NXP
+	def_bool COMMON_CLK && ARCH_LPC18XX
+	---help---
+	  Support for clock providers on NXP platforms.
+
 config COMMON_CLK_PXA
 	def_bool COMMON_CLK && ARCH_PXA
 	---help---

drivers/clk/Makefile

@@ -62,8 +62,8 @@ endif
 obj-$(CONFIG_PLAT_ORION)		+= mvebu/
 obj-$(CONFIG_ARCH_MESON)		+= meson/
 obj-$(CONFIG_ARCH_MXS)			+= mxs/
-obj-$(CONFIG_ARCH_LPC18XX)		+= nxp/
 obj-$(CONFIG_MACH_PISTACHIO)		+= pistachio/
+obj-$(CONFIG_COMMON_CLK_NXP)		+= nxp/
 obj-$(CONFIG_COMMON_CLK_PXA)		+= pxa/
 obj-$(CONFIG_COMMON_CLK_QCOM)		+= qcom/
 obj-$(CONFIG_ARCH_ROCKCHIP)		+= rockchip/