spi: xilinx_spi: Driver clean-up

- Zap unneeded macros
- Re-arrange the code
- Removed __attribute__((weak))
- Replace __func__ macro with func names to save macro transition.
- Re-arranged comment lines.
- Arrange driver code in more readable format[1]

[1]  http://patchwork.ozlabs.org/patch/265683/

Signed-off-by: Jagan Teki <jteki@openedev.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
1 file changed