microblaze: cpu: Delete EXCP_NMI

This define is unused. Remove.

Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

target-microblaze/cpu.h

@@ -36,7 +36,6 @@ typedef struct CPUMBState CPUMBState;
 
 #define ELF_MACHINE	EM_MICROBLAZE
 
-#define EXCP_NMI        1
 #define EXCP_MMU        2
 #define EXCP_IRQ        3
 #define EXCP_BREAK      4