board: am57xx: Rename TARGET_BEAGLE_X15 as TARGET_AM57XX_EVM

board/am57xx supports all boards based on am57xx. Rename the taget
as TARGET_AM57XX_EVM.

Fixes: 74cc8b097d9af ("board: ti: beagle_x15: Rename to indicate support for TI am57xx evms")
Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
diff --git a/arch/arm/cpu/armv7/omap5/Kconfig b/arch/arm/cpu/armv7/omap5/Kconfig
index 026bf24..4fb5ef9 100644
--- a/arch/arm/cpu/armv7/omap5/Kconfig
+++ b/arch/arm/cpu/armv7/omap5/Kconfig
@@ -14,8 +14,8 @@
 	bool "TI DRA7XX"
 	select TI_I2C_BOARD_DETECT
 
-config TARGET_BEAGLE_X15
-	bool "BeagleBoard X15"
+config TARGET_AM57XX_EVM
+	bool "AM57XX"
 	select TI_I2C_BOARD_DETECT
 
 endchoice