More documentation for HE Spatial Reuse Parameter Set configuration

Add a bit more complete documentation on how he_spr_sr_control parameter
is supposed to be used.

Signed-off-by: Jouni Malinen <j@w1.fi>

hostapd/hostapd.conf

@@ -877,18 +877,31 @@ wmm_ac_vo_acm=0
 #he_mu_edca_ac_vo_timer=255
 
 # Spatial Reuse Parameter Set
+#
+# SR Control field value
+# B0 = PSR Disallowed
+# B1 = Non-SRG OBSS PD SR Disallowed
+# B2 = Non-SRG Offset Present
+# B3 = SRG Information Present
+# B4 = HESIGA_Spatial_reuse_value15_allowed
 #he_spr_sr_control
+#
+# Non-SRG OBSS PD Max Offset (included if he_spr_sr_control B2=1)
 #he_spr_non_srg_obss_pd_max_offset
+
+# SRG OBSS PD Min Offset (included if he_spr_sr_control B3=1)
 #he_spr_srg_obss_pd_min_offset
+#
+# SRG OBSS PD Max Offset (included if he_spr_sr_control B3=1)
 #he_spr_srg_obss_pd_max_offset
 #
-# SPR SRG BSS Color
+# SPR SRG BSS Color (included if he_spr_sr_control B3=1)
 # This config represents SRG BSS Color Bitmap field of Spatial Reuse Parameter
 # Set element that indicates the BSS color values used by members of the
 # SRG of which the transmitting STA is a member. The value is in range of 0-63.
 #he_spr_srg_bss_colors=1 2 10 63
 #
-# SPR SRG Partial BSSID
+# SPR SRG Partial BSSID (included if he_spr_sr_control B3=1)
 # This config represents SRG Partial BSSID Bitmap field of Spatial Reuse
 # Parameter Set element that indicates the Partial BSSID values used by members
 # of the SRG of which the transmitting STA is a member. The value range