spi/xlp: SPI controller driver for Netlogic XLP SoCs

Add SPI Master controller driver for the SPI interface on XLP8XX,
XLP3XX, XLP2XX, XLP9XX and XLP5XX family of Netlogic XLP MIPS64 processors.

Signed-off-by: Kamlakant Patel <kamlakant.patel@broadcom.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --cc drivers/spi/Kconfig
Simple merge

diff --cc drivers/spi/Makefile
Simple merge

diff --cc drivers/spi/spi-xlp.c
Simple merge