sys/arm/arm/identcpu-v4.c: fix identify_arm_cpu()

identify_arm_cpu() in sys/arm/arm/identcpu-v4.c incorrectly uses a
u_int8_t variable to store the result of cpu_get_control().
It should really use a u_int variable, the same way as done for cpu_ident()
in the same function, as both cpuid and control registers are 32-bit..
This issue causes users of identcpu-v4 to incorrectly report things such as
icache status (bit 12 in cpu control register) and basically anything
defined in bits above bit 7 :-)

Reviewed by: manu
Sponsored by: Smartcom - Bulgaria AD
Differential Revision: https://reviews.freebsd.org/D9460