Fix various default IRQ priorities

Changes the default IRQ priority level from 0 to 2 for the following
kernel configuration options as priorities 0 and 1 are reserved for the
first 32 IDT entries.

	SHARED_IRQ_0_PRI
	SHARED_IRQ_1_PRI
	I2C_DW_0_INT_PRIORITY
	GPIO_DW_0_PRI
	GPIO_DW_1_PRI
	SPI_INTEL_PORT_0_PRI
	SPI_INTEL_PORT_1_PRI

Change-Id: I0fc821c68156eb1e1fe776b2bd4ff5890bba40e8
Signed-off-by: Peter Mitsis <peter.mitsis@windriver.com>