If LPAE is enabled, 3 level page table is used and the 'SECTION_SIZE'
is (1<<21), so add_buffer_phys_virt() should align to (1 << 21).
(From OE-Core rev: 582cad510953d3540ffe35b10b1ce2a8d034b535)
Signed-off-by: Haiqing Bai <Haiqing.Bai@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>