ARM: pxa: append the definition of CKENC

#define AICSR		__REG(0x41340008)	/* Application Subsystem Interrupt Control/Status Register */

#define CKENA		__REG(0x4134000C)	/* A Clock Enable Register */

#define CKENB		__REG(0x41340010)	/* B Clock Enable Register */

#define CKENC		__REG(0x41340024)	/* C Clock Enable Register */

#define AC97_DIV	__REG(0x41340014)	/* AC97 clock divisor value register */

#define ACCR_XPDIS		(1 << 31)	/* Core PLL Output Disable */