Convert CONFIG_LBA48 et al to Kconfig

This converts the following to Kconfig:
   CONFIG_LBA48
   CONFIG_SYS_64BIT_LBA

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/chromebox_panther_defconfig b/configs/chromebox_panther_defconfig
index c909d31..870843a 100644
--- a/configs/chromebox_panther_defconfig
+++ b/configs/chromebox_panther_defconfig
@@ -53,6 +53,8 @@
 CONFIG_TFTP_TSIZE=y
 CONFIG_REGMAP=y
 CONFIG_SYSCON=y
+CONFIG_LBA48=y
+CONFIG_SYS_64BIT_LBA=y
 CONFIG_CROS_EC=y
 CONFIG_CROS_EC_LPC=y
 CONFIG_RTL8169=y