Convert CONFIG_SYS_FSL_ERRATUM_A010315 to Kconfig option

Move this option to Kconfig and clean up existing uses.

Signed-off-by: York Sun <york.sun@nxp.com>
CC: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
diff --git a/arch/arm/cpu/armv7/ls102xa/Kconfig b/arch/arm/cpu/armv7/ls102xa/Kconfig
new file mode 100644
index 0000000..e88a05e
--- /dev/null
+++ b/arch/arm/cpu/armv7/ls102xa/Kconfig
@@ -0,0 +1,3 @@
+config ARCH_LS1021A
+	bool "Freescale Layerscape LS1021A SoC"
+	select SYS_FSL_ERRATUM_A010315