Compile issue, implicit declaration of function major

[cratuki]

Hi Serge,

I am building on the latest Debian and working through some issues. I will raise issues as independent tickets, as you might not agree with all my solutions.

1. Early in make, I get an error,

qga/commands-posix.c: In function ‘dev_major_minor’:
qga/commands-posix.c:633:21: error: implicit declaration of function ‘major’; did you mean ‘_m_por’? [-Werror=implicit-function-declaration]                                                                                                  
         *devmajor = major(st.st_rdev);
                     ^~~~~                                                                                                                                                                                                                    
                     _m_por  
qga/commands-posix.c:633:21: error: nested extern declaration of ‘major’ [-Werror=nested-externs]
qga/commands-posix.c:634:21: error: implicit declaration of function ‘minor’; did you mean ‘mknod’? [-Werror=implicit-function-declaration]
         *devminor = minor(st.st_rdev);
                     ^~~~~ 
                     mknod                                                                                                                                                                                                                    
qga/commands-posix.c:634:21: error: nested extern declaration of ‘minor’ [-Werror=nested-externs]
cc1: all warnings being treated as errors
make: *** [/home/cturner/opt/20200306.musicbox.cturner.ac.sergev.qemu.mips.pic32/qemu/rules.mak:57: qga/commands-posix.o] Error 1

This can be fixed by changing the import for sys/types.h to sys/sysmacros.h in the qga/commands-posix.c (source: hishamhm/htop#663)