omap5: kconfig: move board select menu and common settings

Becuase the board select menu in arch/arm/Kconfig is too big,
move the OMAP5 board select menu to omap5/Kconfig.

Move also common settings (CONFIG_SYS_CPU="armv7" and
CONFIG_SYS_SOC="omap5").

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Reviewed-by: Tom Rini <trini@ti.com>
Cc: Lokesh Vutla <lokeshvutla@ti.com>
diff --git a/configs/dra7xx_evm_defconfig b/configs/dra7xx_evm_defconfig
index 82cffd7..297c6b5 100644
--- a/configs/dra7xx_evm_defconfig
+++ b/configs/dra7xx_evm_defconfig
@@ -1,4 +1,5 @@
 CONFIG_SPL=y
 CONFIG_SYS_EXTRA_OPTIONS="CONS_INDEX=1"
 +S:CONFIG_ARM=y
++S:CONFIG_OMAP54XX=y
 +S:CONFIG_TARGET_DRA7XX_EVM=y