i7300_idle: Remove this driver

In preparation for removing the idle_notifier, remove its only user, the
i7300_idle driver.

i7300_idle was deployed in 2008 to reduce idle memory power on systems
using the i7300 chipset.  The driver worked by throttling the
fully-buffered DIMMs during idle periods using the IOAT DMA engine.

The driver ran only on the i7300 chip-set, and no other hardware has used
this mechanism.  The driver no longer has a maintainer.

Removing this driver will increase idle power on i7300 systems when they
run the new kernel without the driver.

Signed-off-by: Len Brown <len.brown@intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/ad6a044e57cc75f44cc8621abe846e58f7882243.1479449716.git.len.brown@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

drivers/dma/ioat/registers.h

@@ -106,8 +106,6 @@
 #define IOAT_DMA_COMP_V1			0x0001	/* Compatibility with DMA version 1 */
 #define IOAT_DMA_COMP_V2			0x0002	/* Compatibility with DMA version 2 */
 
-/* IOAT1 define left for i7300_idle driver to not fail compiling */
-#define IOAT1_CHANSTS_OFFSET		0x04
 #define IOAT_CHANSTS_OFFSET		0x08	/* 64-bit Channel Status Register */
 #define IOAT_CHANSTS_COMPLETED_DESCRIPTOR_ADDR	(~0x3fULL)
 #define IOAT_CHANSTS_SOFT_ERR			0x10ULL