sh-sci: update receive error handling for muxed irqs

This patch updates the receive error code for muxed interrupts in the sh-sci driver.

Receive error interrupts may be generated by the hardware if RE or REIE bits in SCSCR are set. Update the muxed interrupt handling code to acknowledge error interrupts if RE or REIE is set, instead of only acknowledging if REIE is set.

Without this patch error interrupts may be generated but never acked resulting in a "nobody cared" crash.

The sh7724 processor has two on-chip r8a66597 blocks, so add it to the list of processors for SUPERH_ON_CHIP_R8A66597.

Add USB host support for port CN27 on the Solution Engine 7724 board. The r8a66597-hcd driver is hooked up as a platform device and some registers are configured to enable the USB host function. The hardware driving the USB port is the on-chip USB0 block in the sh7724 processor configured as USB host controller.