efi: Rearrange the Kconfig for CMD_BOOTEFI_BOOTMGR

The command should not be used to enable library functionality. Add a
new BOOTEFI_BOOTMGR Kconfig for that. Adjust the conditions so that the
same code is built.

Signed-off-by: Simon Glass <sjg@chromium.org>
Suggested-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
3 files changed