linuxkpi: Define boot_cpu_data.x86_max_cores

Reviewed by:	manu
Approved by:	manu
Differential Revision:	https://reviews.freebsd.org/D36971

sys/compat/linuxkpi/common/include/asm/processor.h

@@ -36,6 +36,7 @@
 struct cpuinfo_x86 {
 	uint8_t		x86;
 	uint16_t	x86_clflush_size;
+	uint16_t	x86_max_cores;
 };
 
 extern struct cpuinfo_x86	boot_cpu_data;

sys/compat/linuxkpi/common/src/linux_compat.c

@@ -2766,6 +2766,7 @@ linux_compat_init(void *arg)
 #if defined(__i386__) || defined(__amd64__)
 	linux_cpu_has_clflush = (cpu_feature & CPUID_CLFSH);
 	boot_cpu_data.x86_clflush_size = cpu_clflush_line_size;
+	boot_cpu_data.x86_max_cores = mp_ncpus;
 	boot_cpu_data.x86 = ((cpu_id & 0xf0000) >> 12) | ((cpu_id & 0xf0) >> 4);
 #endif
 	rw_init(&linux_vma_lock, "lkpi-vma-lock");