efi: Add a way to obtain boot services in the app

Add a function to return this information along with a stub for the
efi_info_get() function, since calling it otherwise hangs U-Boot.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

include/efi.h

@@ -444,9 +444,15 @@ extern char _binary_u_boot_bin_start[], _binary_u_boot_bin_end[];
  *
  * @return pointer to EFI system table
  */
-
 struct efi_system_table *efi_get_sys_table(void);
 
+/**
+ * efi_get_boot() - Get access to the EFI boot services table
+ *
+ * @return pointer to EFI boot services table
+ */
+struct efi_boot_services *efi_get_boot(void);
+
 /**
  * efi_get_ram_base() - Find the base of RAM
  *