spi: cadence_qspi_apb: Use BIT macro

Replace numerical bit shift with BIT macro
in cadence_qspi_apb

:%s/(1 << nr)/BIT(nr)/g
where nr = 0, 1, 2 .... 31

Cc: Stefan Roese <sr@denx.de>
Cc: Marek Vasut <marex@denx.de>
Acked-by: Vikas Manocha <vikas.manocha@st.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Jagan Teki <jteki@openedev.com>