efi_loader: Extract adding a conventional memory in separate routine

Adding a conventional memory region to the memory map may require ram_top
limitation and it can be also commonly used. Extract adding a conventional
memory to the memory map in a separate routine for generic use.

Signed-off-by: Aiden Park <aiden.park@intel.com>
Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2 files changed