spi: pic32-sqi: Fix linker error, undefined reference to `bad_dma_ops'.

Even if DMA support is disabled code using DMA mapping APIs compiles fine,
but fails in linking.
-------
drivers/built-in.o: In function `ring_desc_ring_free':
spi-pic32-sqi.c:(.text+0x2cfbe0): undefined reference to `bad_dma_ops'
spi-pic32-sqi.c:(.text+0x2cfbe4): undefined reference to `bad_dma_ops'
drivers/built-in.o: In function `pic32_sqi_probe':
spi-pic32-sqi.c:(.text+0x2cfe48): undefined reference to `bad_dma_ops'
spi-pic32-sqi.c:(.text+0x2cfeb0): undefined reference to `bad_dma_ops'
spi-pic32-sqi.c:(.text+0x2cff38): undefined reference to `bad_dma_ops'
--------
Correct dependency by adding 'depends on HAS_DMA' in Kconfig.

Signed-off-by: Purna Chandra Mandal <purna.mandal@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>