V4L/DVB (5520): Add support for the extra keys in the black Technotrend 1500 IR

It has come to my knowledge that the Technotrend 1500 DVB cards have 
been sold bundled with at least two different kinds of remotes, a grey 
one and a black one. 
This patch adds support for the extra keys in the black remote to 
ir-keymaps.c.

Signed-off-by: Ville-Pekka Vainio <vpivaini@cs.helsinki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>