vexpress64: kconfig: consolidate CONFIG_TARGET_VEXPRESS_AEMV8A_SEMI

We do not have to distinguish CONFIG_TARGET_VEXPRESS_AEMV8A_SEMI
from CONFIG_TARGET_VEXPRESS_AEMV8A.  Rename the former to the latter.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Reviewed-by: Steve Rae <srae@broadcom.com>
Cc: David Feng <fenghua@phytium.com.cn>
diff --git a/configs/vexpress_aemv8a_semi_defconfig b/configs/vexpress_aemv8a_semi_defconfig
index e6dd8e7..24b868c 100644
--- a/configs/vexpress_aemv8a_semi_defconfig
+++ b/configs/vexpress_aemv8a_semi_defconfig
@@ -1,3 +1,3 @@
 CONFIG_SYS_EXTRA_OPTIONS="ARM64,SEMIHOSTING,BASE_FVP"
 CONFIG_ARM=y
-CONFIG_TARGET_VEXPRESS_AEMV8A_SEMI=y
+CONFIG_TARGET_VEXPRESS_AEMV8A=y