ARM: Use a 32-bit variable for control register instead of 8-bit

[sgalabov]

Summary

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 :-)