spl: set SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR to 0x4000 for rockchip

Rockchip use a 'loader2' partition for U-Boot, so u-boot.bin or
u-boot.itb load by SPL need to locate at0x4000. Detail here:
http://opensource.rock-chips.com/wiki_Boot_option

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>

common/spl/Kconfig

@@ -142,11 +142,12 @@ config SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR
 	default 0x50 if ARCH_SUNXI
 	default 0x75 if ARCH_DAVINCI
 	default 0x8a if ARCH_MX6
-	default 0x100 if ARCH_ROCKCHIP || ARCH_UNIPHIER
+	default 0x100 if ARCH_UNIPHIER
 	default 0x140 if ARCH_MVEBU
 	default 0x200 if ARCH_SOCFPGA || ARCH_AT91
 	default 0x300 if ARCH_ZYNQ || ARCH_KEYSTONE || OMAP34XX || OMAP44XX || \
 		         OMAP54XX || AM33XX || AM43XX
+	default 0x4000 if ARCH_ROCKCHIP
 	help
 	  Address on the MMC to load U-Boot from, when the MMC is being used
 	  in raw mode. Units: MMC sectors (1 sector = 512 bytes).