enable spi driver model for dra74_evm as ti_qspi supports
driver model
Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com> Reviewed-by: Simon Glass <sjg@chromium.org> Reviewed-by: Tom Rini <trini@konsulko.com> Reviewed-by: Jagan Teki <jteki@openedev.com>