arm: lpc32xx: move SoC to mach-lpc32xx

Following the example of most other SoCs in arch/$(ARCH)/cpu/$(CPU)/$(SOC)
move the lpc32xx code from arch/arm/cpu/arm926ejs/lpc32xx to
arch/arm/mach-lpc32xx.

Following the checklist from
commit 01f14456306c ("ARM: prepare for moving SoC sources into mach-*"):

    [1] move files from arch/arm/cpu/arm926ejs/lpc32xx to arch/arm/mach-lpx32xx
    [2] add machine entry to arch/arm/Makefile
    [3] remove "obj-y += ..." from arch/arm/cpu/arm926ejs/Makefile
    [4] fix the Kconfig file path in arch/arm/Kconfig
    [5] (no MAINTAINERS update)

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Trevor Woerner <twoerner@gmail.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 0d46308..bd802b3 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1777,7 +1777,7 @@
 
 source "arch/arm/mach-kirkwood/Kconfig"
 
-source "arch/arm/cpu/arm926ejs/lpc32xx/Kconfig"
+source "arch/arm/mach-lpc32xx/Kconfig"
 
 source "arch/arm/mach-mvebu/Kconfig"