Patch makes the OMAP2 McSPI module to use interface and functional clocks
only when needed and inserts timeout handling in function
omap2_mcspi_txrx_pio.

These are originally developed by Samuel Ortiz <samuel.ortiz@solidboot.com>
and Juha Yrjola <juha.yrjola@solidboot.com>.
Signed-off-by: Jarkko Nikula <jarkko.nikula@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>