[MIPS] Delete CONFIG_MSP_FPGA

Originally noticed by Jiri Olsa <[e-mail]>.

Signed-off-by: Ralf Baechle <[e-mail]>

include/asm-mips/pmc-sierra/msp71xx/msp_regs.h

···
  * UART defines                                                            *
  ***************************************************************************
  */
-#ifndef CONFIG_MSP_FPGA
 #define MSP_BASE_BAUD		25000000
-#else
-#define MSP_BASE_BAUD		6000000
-#endif
 #define MSP_UART_REG_LEN	0x20
 
 /*