compat: update and improve detection of CentOS Stream 8

CentOS Stream 8 by now (4.18.0-301.1.el8) reports RHEL_MINOR=5. The
current RHEL 8 minor release is still 3. RHEL 8.4 is in beta. Replace
equal comparison by greater equal to (hopefully) be a little bit more
future proof.

Signed-off-by: Peter Georg <peter.georg@physik.uni-regensburg.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

Author: Peter Georg

src/compat/compat-asm.h

@@ -15,7 +15,7 @@
 #define ISRHEL7
 #elif RHEL_MAJOR == 8
 #define ISRHEL8
-#if RHEL_MINOR == 4
+#if RHEL_MINOR >= 4
 #define ISCENTOS8S
 #endif
 #endif

src/compat/compat.h

@@ -16,7 +16,7 @@
 #define ISRHEL7
 #elif RHEL_MAJOR == 8
 #define ISRHEL8
-#if RHEL_MINOR == 4
+#if RHEL_MINOR >= 4
 #define ISCENTOS8S
 #endif
 #endif