board: remove capsule update support in set_dfu_alt_info()

Now that capsule update sets the dfu_alt_info environment variable
explicitly, there is no need to support it in the set_dfu_alt_info()
function. Decouple SET_DFU_ALT_INFO from EFI_CAPSULE_FIRMWARE_FIT and
EFI_CAPSULE_FIRMWARE_RAW. For many boards, this was the only use of
set_dfu_alt_info() so remove the function entirely.

Fixes: a9e6f01a94 ("efi: Define set_dfu_alt_info() for boards with UEFI capsule update enabled")

Signed-off-by: Jonathan Humphreys <j-humphreys@ti.com>
Signed-off-by: Michal Simek <michal.simek@amd.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> # for board/libre-computer/*
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Wadim Egorov <w.egorov@phytec.de> # for

lib/efi_loader/Kconfig

@@ -305,7 +305,6 @@ config EFI_CAPSULE_FIRMWARE_FIT
 	depends on EFI_CAPSULE_FIRMWARE_MANAGEMENT
 	select UPDATE_FIT
 	select DFU
-	select SET_DFU_ALT_INFO
 	select EFI_CAPSULE_FIRMWARE
 	help
 	  Select this option if you want to enable firmware management protocol
@@ -317,7 +316,6 @@ config EFI_CAPSULE_FIRMWARE_RAW
 	depends on SANDBOX || (!SANDBOX && !EFI_CAPSULE_FIRMWARE_FIT)
 	select DFU_WRITE_ALT
 	select DFU
-	select SET_DFU_ALT_INFO
 	select EFI_CAPSULE_FIRMWARE
 	help
 	  Select this option if you want to enable firmware management protocol

lib/efi_loader/efi_firmware.c

@@ -56,11 +56,6 @@ struct fmp_state {
 	u32 last_attempt_status; /* not used */
 };
 
-__weak void set_dfu_alt_info(char *interface, char *devstr)
-{
-	env_set("dfu_alt_info", update_info.dfu_string);
-}
-
 /**
  * efi_firmware_get_image_type_id - get image_type_id
  * @image_index:	image index