kconfig: remove meaningless prefixes in defconfig files

Since commit e02ee2548afe (kconfig: switch to single .config
configuration), the prefixes in defconfig files such as "+S:",
"+ST:", etc., are meaningless.

This commit was generated by the following command:

  find configs -name '*_defconfig' | xargs sed -i 's/^+*S*T*://'

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/configs/mk802_a10s_defconfig b/configs/mk802_a10s_defconfig
index cafcbaa..701b92b 100644
--- a/configs/mk802_a10s_defconfig
+++ b/configs/mk802_a10s_defconfig
@@ -2,9 +2,9 @@
 CONFIG_SYS_EXTRA_OPTIONS="AXP152_POWER,USB_EHCI"
 CONFIG_FDTFILE="sun5i-a10s-mk802.dtb"
 CONFIG_USB1_VBUS_PIN="PB10"
-+S:CONFIG_ARM=y
-+S:CONFIG_ARCH_SUNXI=y
-+S:CONFIG_MACH_SUN5I=y
-+S:CONFIG_DRAM_CLK=432
-+S:CONFIG_DRAM_ZQ=123
-+S:CONFIG_DRAM_EMR1=0
+CONFIG_ARM=y
+CONFIG_ARCH_SUNXI=y
+CONFIG_MACH_SUN5I=y
+CONFIG_DRAM_CLK=432
+CONFIG_DRAM_ZQ=123
+CONFIG_DRAM_EMR1=0