linux(4): Use Linux dev_t type for mknod syscalls dev argument

As of version 2.6.0 of the Linux kernel, dev_t is a 32-bit unsigned integer
on all platforms. Prior the 2.6 kernel dev_t type was an unsigned short.
However, since the firs commit of the Linuxulator, mknod syscall get int dev
argument.
Also, there is some confusion here, while the kernel declares a dev_t type
as a 32-bit sized, the user-space dev_t type can be size of 64 bits, e.g.,
in the Glibc library.
To avoid confusion and to help porting of the Linuxulator to other platforms
use explicit l_dev_t for dev argument of mknod syscalls.

sys/amd64/linux/syscalls.master

@@ -874,7 +874,7 @@
 		int linux_mknod(
 		    char *path,
 		    l_mode_t mode,
-		    l_uint dev
+		    l_dev_t dev
 		);
 	}
 134	AUE_USELIB	UNIMPL	uselib
@@ -1503,7 +1503,7 @@
 		    l_int dfd,
 		    const char *filename,
 		    l_mode_t mode,
-		    l_uint dev
+		    l_dev_t dev
 		);
 	}
 260	AUE_FCHOWNAT	STD {

sys/amd64/linux32/syscalls.master

@@ -1616,7 +1616,7 @@
 		    l_int dfd,
 		    const char *filename,
 		    l_int mode,
-		    l_uint dev
+		    l_dev_t dev
 		);
 	}
 298	AUE_FCHOWNAT	STD {

sys/arm64/linux/syscalls.master

@@ -204,7 +204,7 @@
 		    l_int dfd,
 		    const char *filename,
 		    l_int mode,
-		    l_uint dev
+		    l_dev_t dev
 		);
 	}
 34	AUE_MKDIRAT	STD	{

sys/i386/linux/syscalls.master

@@ -1633,7 +1633,7 @@
 		    l_int dfd,
 		    const char *filename,
 		    l_int mode,
-		    l_uint dev
+		    l_dev_t dev
 		);
 	}
 298	AUE_FCHOWNAT	STD {