staging: rtl8723bs: Replace network magic numbers with EtherType macros

staging: rtl8723bs: Replace network magic numbers with EtherType macros

Replace hardcoded magic numbers for network protocols (e.g., 0x0806
for ARP, 0x888e for EAPOL) with their standard EtherType macro
equivalents (ETH_P_ARP, ETH_P_PAE) defined in <linux/if_ether.h>.

This change improves code readability and aligns the driver with
standard Linux networking definitions.

Signed-off-by: Marcos Andrade <marcosandrade95963@gmail.com>
Reviewed-by: Ethan Tidmore <ethantidmore06@gmail.com>
Link: https://patch.msgid.link/20260316221924.4904-2-marcosandrade95963@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>