efi: fix memory calculation overflow on 32-bit systems

There are Cubox-i machines out there with nearly 4 GiB of RAM.  The
RAM starts at 0x10000000 with a size of 0xf0000000.  Thus the end
of RAM is at 0x100000000.  This overflows a 32-bit integer, which
should be fine since in the EFI memory code the variables used are
all 64-bit with a fixed size.  Unfortunately EFI_PAGE_MASK, which is
used in the EFI memory code to remove the lower bits, is based on
the EFI_PAGE_SIZE macro which, uses 1UL with a shift.  This means
the resulting mask is UL, which is only 32-bit on ARMv7.  Use ULL to
make sure that even on 32-bit platforms we use a 64-bit long mask.
Without this there will be no memory available in the EFI memory map
and bootefi will fail allocating pages.

Signed-off-by: Patrick Wildt <patrick@blueri.se>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Patrick Delaunay <patrick.delaunay@st.com>