[BUG] efi_check_allocated() only checks start address

[Heinrich Schuchardt]

AllocatePages() and FreePages() call efi_check_allocated() to check if a 
memory address is allocated or not.

The function should consider the number of pages in the request and 
either check if the full range is deallocated or the full range is 
allocated.

https://source.denx.de/u-boot/custodians/u-boot-efi/-/issues/7

Best regards

Heinrich