staging: sm750fb: Prefer using the BIT macro

Challenge suggested by coccinelle.

Replace bit shifting on 1 with the BIT(x) macro.
Coccinelle script:

@@
constant c;
@@

-(1 << c)
+BIT(c)

Signed-off-by: Sanjana Sanikommu <sanjana99reddy99@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>