dissectors: 80211_mac_hdr: Remove usage of binary constants

Binary constants are not C99, but a GCC extension. Moreover, Mohan
reports compilation errors resulting from these constructs when using a
PowerPC cross-compiler. Thus, replace them by the corresponding
hexadecimal constants.

Reported-by: Mohan Kannekanti <mohan.kannekanti@gmail.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>