Qualcomm SLIMBUS controller

Required properties:

 - reg : Offset and length of the register region(s) for the device
 - reg-names : Register region name(s) referenced in reg above
	 Required register resource entries are:
	 "slimbus_physical": Physical adderss of controller register blocks
	 "slimbus_bam_physical": Physical address of Bus Access Module (BAM)
				 for this controller
 - compatible : should be "qcom,slim-msm"
 - cell-index : SLIMBUS number used for this controller
 - interrupts : Interrupt numbers used by this controller
 - interrupt-names : Required interrupt resource entries are:
	"slimbus_irq" : Interrupt for SLIMBUS core
	"slimbus_bam_irq" : Interrupt for controller core's BAM

Optional property:
 - reg entry for slew rate : If slew rate control register is provided, this
	 entry should be used.
 - reg-name for slew rate: "slimbus_slew_reg"
 - qcom,min-clk-gear : Minimum clock gear at which this controller can be run
		 (range: 1-10)
		 Default value will be 1 if this entry is not specified
 - qcom,max-clk-gear: Maximum clock gear at which this controller can be run
		 (range: 1-10)
		 Default value will be 10 if this entry is not specified
 - qcom,rxreg-access: This boolean indicates that slimbus RX should use direct
		 register access to receive data. This flag is only needed if
		 BAM pipe is not available to receive data from slimbus
Example:
	slim@fe12f000 {
		cell-index = <1>;
		compatible = "qcom,slim-msm";
		reg = <0xfe12f000 0x35000>,
		      <0xfe104000 0x20000>;
		reg-names = "slimbus_physical", "slimbus_bam_physical";
		interrupts = <0 163 0 0 164 0>;
		interrupt-names = "slimbus_irq", "slimbus_bam_irq";
		qcom,min-clk-gear = <10>;
		qcom,rxreg-access;
	};
