mx5: board: code clean up for checkboard code

The boot cause code has been factor out to soc common
code,we need drop the part from the board support code

This patch also remove the redundant cpu version print

Signed-off-by: Jason Liu <jason.hui@linaro.org>
diff --git a/board/freescale/mx51evk/mx51evk.c b/board/freescale/mx51evk/mx51evk.c
index 02a765d..e2d3d74 100644
--- a/board/freescale/mx51evk/mx51evk.c
+++ b/board/freescale/mx51evk/mx51evk.c
@@ -431,41 +431,7 @@
 
 int checkboard(void)
 {
-	puts("Board: MX51EVK ");
+	puts("Board: MX51EVK\n");
 
-	switch (system_rev & 0xff) {
-	case CHIP_REV_3_0:
-		puts("3.0 [");
-		break;
-	case CHIP_REV_2_5:
-		puts("2.5 [");
-		break;
-	case CHIP_REV_2_0:
-		puts("2.0 [");
-		break;
-	case CHIP_REV_1_1:
-		puts("1.1 [");
-		break;
-	case CHIP_REV_1_0:
-	default:
-		puts("1.0 [");
-		break;
-	}
-
-	switch (__raw_readl(SRC_BASE_ADDR + 0x8)) {
-	case 0x0001:
-		puts("POR");
-		break;
-	case 0x0009:
-		puts("RST");
-		break;
-	case 0x0010:
-	case 0x0011:
-		puts("WDOG");
-		break;
-	default:
-		puts("unknown");
-	}
-	puts("]\n");
 	return 0;
 }