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/Mele_I7_defconfig b/configs/Mele_I7_defconfig
index e2c63c5..0e9a950 100644
--- a/configs/Mele_I7_defconfig
+++ b/configs/Mele_I7_defconfig
@@ -7,20 +7,20 @@
 CONFIG_SPL=y
 CONFIG_SYS_EXTRA_OPTIONS="USB_EHCI,SUNXI_GMAC"
 CONFIG_FDTFILE="sun6i-a31-i7.dtb"
-+S:CONFIG_ARM=y
-+S:CONFIG_ARCH_SUNXI=y
-+S:CONFIG_MACH_SUN6I=y
-+S:CONFIG_DRAM_CLK=312
-+S:CONFIG_DRAM_ZQ=120
+CONFIG_ARM=y
+CONFIG_ARCH_SUNXI=y
+CONFIG_MACH_SUN6I=y
+CONFIG_DRAM_CLK=312
+CONFIG_DRAM_ZQ=120
 # The Mele I7 uses 3.3V for general IO
-+S:CONFIG_AXP221_DCDC1_VOLT=3300
+CONFIG_AXP221_DCDC1_VOLT=3300
 # Ethernet phy power
-+S:CONFIG_AXP221_DLDO1_VOLT=3300
+CONFIG_AXP221_DLDO1_VOLT=3300
 # USB hub power
-+S:CONFIG_AXP221_DLDO4_VOLT=3300
+CONFIG_AXP221_DLDO4_VOLT=3300
 # Wifi power
-+S:CONFIG_AXP221_ALDO1_VOLT=3300
+CONFIG_AXP221_ALDO1_VOLT=3300
 # Vbus gpio for usb1
-+S:CONFIG_USB1_VBUS_PIN="PC27"
+CONFIG_USB1_VBUS_PIN="PC27"
 # No Vbus gpio for usb2
-+S:CONFIG_USB2_VBUS_PIN=""
+CONFIG_USB2_VBUS_PIN=""