ARM: UniPhier: use CONFIG_SPL_STACK to define SPL stack pointer

Ifdef conditionals for CONFIG options are not Kconfig-friendly.
Instead, define CONFIG_SPL_STACK to prepare for Kconfig moves.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

arch/arm/mach-uniphier/init_page_table.S

@@ -1,3 +1,11 @@
+/*
+ * Copyright (C) 2015 Panasonic Corporation
+ * Copyright (C) 2015 Socionext Inc.
+ *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
 #include <config.h>
 #include <linux/linkage.h>
 
@@ -8,7 +16,7 @@
 #define NORMAL	0x0000000e /* Normal Memory Write-Back, No Write-Allocate */
 
 #define TEXT_SECTION	((CONFIG_SPL_TEXT_BASE) >> (SECTION_SHIFT))
-#define STACK_SECTION	((CONFIG_SYS_INIT_SP_ADDR) >> (SECTION_SHIFT))
+#define STACK_SECTION	((CONFIG_SPL_STACK) >> (SECTION_SHIFT))
 
 	.section ".rodata"
 	.align 14

arch/arm/mach-uniphier/lowlevel_init.S

@@ -1,6 +1,7 @@
 /*
- * Copyright (C) 2012-2014 Panasonic Corporation
- *   Author: Masahiro Yamada <yamada.m@jp.panasonic.com>
+ * Copyright (C) 2012-2015 Panasonic Corporation
+ * Copyright (C) 2015      Socionext Inc.
+ *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */
@@ -142,7 +143,7 @@ ENTRY(setup_init_ram)
 	ldr	r0, = 0x00408006	@ touch to zero with address range
 	ldr	r1, = SSCOQM
 	str	r0, [r1]
-	ldr	r0, = (CONFIG_SYS_INIT_SP_ADDR - BOOT_RAM_SIZE)	@ base address
+	ldr	r0, = (CONFIG_SPL_STACK - BOOT_RAM_SIZE)	@ base address
 	ldr	r1, = SSCOQAD
 	str	r0, [r1]
 	ldr	r0, = BOOT_RAM_SIZE

include/configs/uniphier.h

@@ -280,11 +280,8 @@
 #define CONFIG_SKIP_LOWLEVEL_INIT
 #endif
 
-#ifdef CONFIG_SPL_BUILD
-#define CONFIG_SYS_INIT_SP_ADDR		(0x0ff08000)
-#else
+#define CONFIG_SPL_STACK		(0x0ff08000)
 #define CONFIG_SYS_INIT_SP_ADDR		((CONFIG_SYS_TEXT_BASE) - 0x00001000)
-#endif
 
 #define CONFIG_PANIC_HANG