riscv: sifive: Rename fu540 board to unleashed

In preparation to add SiFive Unmatched board support, let's rename
the existing fu540 board to unleashed.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
diff --git a/common/spl/Kconfig b/common/spl/Kconfig
index 0711cbf..0f528f3 100644
--- a/common/spl/Kconfig
+++ b/common/spl/Kconfig
@@ -330,7 +330,8 @@
 		     ARCH_MX6 || ARCH_MX7 || \
 		     ARCH_ROCKCHIP || ARCH_MVEBU ||  ARCH_SOCFPGA || \
 		     ARCH_AT91 || ARCH_ZYNQ || ARCH_KEYSTONE || OMAP34XX || \
-		     OMAP44XX || OMAP54XX || AM33XX || AM43XX || TARGET_SIFIVE_FU540
+		     OMAP44XX || OMAP54XX || AM33XX || AM43XX || \
+		     TARGET_SIFIVE_UNLEASHED
 	help
 	  Use sector number for specifying U-Boot location on MMC/SD in
 	  raw mode.
@@ -347,7 +348,7 @@
 	default 0x300 if ARCH_ZYNQ || ARCH_KEYSTONE || OMAP34XX || OMAP44XX || \
 		         OMAP54XX || AM33XX || AM43XX || ARCH_K3
 	default 0x4000 if ARCH_ROCKCHIP
-	default 0x822 if TARGET_SIFIVE_FU540
+	default 0x822 if TARGET_SIFIVE_UNLEASHED
 	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).