efi_loader: fix memory allocation on sandbox

efi_loader: fix memory allocation on sandbox

Commit 7b78d6438a2b ("efi_loader: Reserve unaccessible memory") introduced
a comparison between RAM top and RAM start that was not known at the time
when the patch of commit 49759743bf09 ("efi_loader: eliminate sandbox
addresses") was written.

The sandbox uses an address space that is only relevant in the sandbox
context. We have to map ram_top from the sandbox address space to the
physical address space before using it in the EFI subsystem.

Fixes: 49759743bf09 ("efi_loader: eliminate sandbox addresses")
Fixes: 7b78d6438a2b ("efi_loader: Reserve unaccessible memory")
Signed-off-by: Heinrich Schuchardt <[email protected]>
Reviewed-by: Simon Glass <[email protected]>
Signed-off-by: Alexander Graf <[email protected]>