ARM: imx6ul: Move liteSOM source to SoC directory

Moving arch/arm/mach-litesom/ to arch/arm/cpu/armv7/mx6/ was requested
in [1] during discussion of chiliSOM support patches.

[1] http://lists.denx.de/pipermail/u-boot/2017-January/279137.html

Suggested-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

arch/arm/include/asm/arch-mx6/litesom.h

@@ -0,0 +1,16 @@
+/*
+ * Copyright (C) 2016 Grinn
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __ARCH_ARM_MX6UL_LITESOM_H__
+#define __ARCH_ARM_MX6UL_LITESOM_H__
+
+int litesom_mmc_init(bd_t *bis);
+
+#ifdef CONFIG_SPL_BUILD
+void litesom_init_f(void);
+#endif
+
+#endif