This commit adds new files that support functionality of QSPI driver in
SPI Master Mode. This functionality is included in new files sam_qspi_spi.x
to avoid too much mess in the source code. QSPI in SPI mode can be turn
on by config option SAMV7_QSPI_SPI_MODE.
Signed-off-by: Michal Lenc <michallenc@seznam.cz>