ARM: uniphier: allow to enable multiple SoCs

Before this commit, the Kconfig menu in mach-uniphier only allowed us
to choose one SoC to be compiled.  Each SoC has its own defconfig file
for the build-test coverage.  Consequently, some defconfig files are
duplicated with only the difference in CONFIG_DEFAULT_DEVICE_TREE and
CONFIG_{SOC_NAME}=y.

Now, most of board-specific parameters have been moved to device trees,
so it makes sense to include init code of multiple SoCs into a single
image as long as the SoCs have similar architecture.  In fact, some
SoCs of UniPhier family are very similar:
 - PH1-LD4 and PH1-sLD8
 - PH1-LD6b and ProXstream2 (will be added in the upcoming commit)

This commit will be helpful to merge some defconfig files for better
maintainability.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/arch/arm/mach-uniphier/early-pinctrl/early-pinctrl-ph1-sld3.c b/arch/arm/mach-uniphier/early-pinctrl/early-pinctrl-ph1-sld3.c
new file mode 100644
index 0000000..1bb9375
--- /dev/null
+++ b/arch/arm/mach-uniphier/early-pinctrl/early-pinctrl-ph1-sld3.c
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2011-2015 Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <mach/init.h>
+#include <mach/sg-regs.h>
+
+int ph1_sld3_early_pin_init(const struct uniphier_board_data *bd)
+{
+	/* Comment format:    PAD Name -> Function Name */
+
+#ifdef CONFIG_UNIPHIER_SERIAL
+	sg_set_pinsel(63, 0, 4, 4);	/* RXD0 */
+	sg_set_pinsel(64, 1, 4, 4);	/* TXD0 */
+
+	sg_set_pinsel(65, 0, 4, 4);	/* RXD1 */
+	sg_set_pinsel(66, 1, 4, 4);	/* TXD1 */
+
+	sg_set_pinsel(96, 2, 4, 4);	/* RXD2 */
+	sg_set_pinsel(102, 2, 4, 4);	/* TXD2 */
+#endif
+
+	return 0;
+}