x86: kconfig: Imply DM uclass drivers

Now that all x86 boards have been converted to use DM, we can imply
these uclass drivers (DM_ETH, DM_RTC, DM_USB, DM_VIDEO) from the
top level.

Previously DM_GPIO, DM_KEYBOARD, DM_SERIAL, DM_SPI, DM_SPI_FLASH
are selected. Change to use 'imply' to allow them to be removed.

Note with this change, chromebook_link64 build fails:

common/built-in.o:(.data.env_htab+0xc): undefined reference to 'env_flags_validate'
lib/built-in.o: In function `hsearch_r':
lib/hashtable.c:380: undefined reference to 'env_callback_init'
lib/hashtable.c:382: undefined reference to 'env_flags_init'
make[1]: *** [spl/u-boot-spl] Error 1

CONFIG_SPL_ENV_SUPPORT is required for chromebook_link64 to build
again. This is just a workaround as it is not needed at all. See
commit bda40d5 "x86: qemu: Add a config for 64-bit U-Boot" for
the same issue seen on QEMU 64-bit target.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/efi-x86_defconfig b/configs/efi-x86_defconfig
index 416b544..47843f7 100644
--- a/configs/efi-x86_defconfig
+++ b/configs/efi-x86_defconfig
@@ -5,7 +5,6 @@
 CONFIG_DEBUG_UART=y
 CONFIG_FIT=y
 CONFIG_ENV_IS_NOWHERE=y
-CONFIG_CONSOLE_MUX=y
 CONFIG_SYS_CONSOLE_INFO_QUIET=y
 CONFIG_HUSH_PARSER=y
 # CONFIG_CMD_BOOTM is not set
@@ -18,7 +17,6 @@
 # CONFIG_CMD_NET is not set
 CONFIG_CMD_DHCP=y
 CONFIG_CMD_PING=y
-CONFIG_CMD_DATE=y
 CONFIG_CMD_TIME=y
 CONFIG_CMD_EXT2=y
 CONFIG_CMD_EXT4=y
@@ -29,6 +27,7 @@
 CONFIG_ISO_PARTITION=y
 CONFIG_EFI_PARTITION=y
 CONFIG_OF_EMBED=y
+# CONFIG_DM_ETH is not set
 CONFIG_DEBUG_EFI_CONSOLE=y
 CONFIG_DEBUG_UART_BASE=0
 CONFIG_DEBUG_UART_CLOCK=0