dmaengine: qcom: Add support for GPI DMA engine

Add dmaengine framework support for QCOM GPI DMA controller.
GPI controller can be used by peripheral buses such as I2C,
UART, and SPI for transferring data between system memory
and peripheral.

CRs-Fixed: 2042764
Change-Id: I645f52361dbd8a0588d65b23c6a1b2202a97cbda
Signed-off-by: Sujeev Dias <sdias@codeaurora.org>