davinci: kconfig: move board select menu and common settings

Becuase the board select menu in arch/arm/Kconfig is too big,
move the Davinci board select menu to davinci/Kconfig.

Move also common settings (CONFIG_SYS_CPU="arm926ejs" and
CONFIG_SYS_SOC="davinci").

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Reviewed-by: Tom Rini <trini@ti.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: Sandeep Paulraj <s-paulraj@ti.com>
diff --git a/configs/da830evm_defconfig b/configs/da830evm_defconfig
index 49e74c3..d27cdb0 100644
--- a/configs/da830evm_defconfig
+++ b/configs/da830evm_defconfig
@@ -1,2 +1,3 @@
 CONFIG_ARM=y
+CONFIG_ARCH_DAVINCI=y
 CONFIG_TARGET_DA830EVM=y