V4L/DVB (13682): dib8000: make some constant static

Eliminate the following sparse warnings (see "make C=1"):
 * dib8000.c:125:15: warning: symbol 'coeff_2k_sb_1seg_dqpsk' was not declared. Should it be static?
 * dib8000.c:130:15: warning: symbol 'coeff_2k_sb_1seg' was not declared. Should it be static?
 * dib8000.c:134:15: warning: symbol 'coeff_2k_sb_3seg_0dqpsk_1dqpsk' was not declared. Should it be static?
 * dib8000.c:139:15: warning: symbol 'coeff_2k_sb_3seg_0dqpsk' was not declared. Should it be static?
 * dib8000.c:144:15: warning: symbol 'coeff_2k_sb_3seg_1dqpsk' was not declared. Should it be static?
 * dib8000.c:149:15: warning: symbol 'coeff_2k_sb_3seg' was not declared. Should it be static?
 * dib8000.c:154:15: warning: symbol 'coeff_4k_sb_1seg_dqpsk' was not declared. Should it be static?
 * dib8000.c:159:15: warning: symbol 'coeff_4k_sb_1seg' was not declared. Should it be static?
 * dib8000.c:164:15: warning: symbol 'coeff_4k_sb_3seg_0dqpsk_1dqpsk' was not declared. Should it be static?
 * dib8000.c:169:15: warning: symbol 'coeff_4k_sb_3seg_0dqpsk' was not declared. Should it be static?
 * dib8000.c:174:15: warning: symbol 'coeff_4k_sb_3seg_1dqpsk' was not declared. Should it be static?
 * dib8000.c:179:15: warning: symbol 'coeff_4k_sb_3seg' was not declared. Should it be static?
 * dib8000.c:184:15: warning: symbol 'coeff_8k_sb_1seg_dqpsk' was not declared. Should it be static?
 * dib8000.c:189:15: warning: symbol 'coeff_8k_sb_1seg' was not declared. Should it be static?
 * dib8000.c:194:15: warning: symbol 'coeff_8k_sb_3seg_0dqpsk_1dqpsk' was not declared. Should it be static?
 * dib8000.c:199:15: warning: symbol 'coeff_8k_sb_3seg_0dqpsk' was not declared. Should it be static?
 * dib8000.c:204:15: warning: symbol 'coeff_8k_sb_3seg_1dqpsk' was not declared. Should it be static?
 * dib8000.c:209:15: warning: symbol 'coeff_8k_sb_3seg' was not declared. Should it be static?
 * dib8000.c:214:15: warning: symbol 'ana_fe_coeff_3seg' was not declared. Should it be static?
 * dib8000.c:218:15: warning: symbol 'ana_fe_coeff_1seg' was not declared. Should it be static?
 * dib8000.c:222:15: warning: symbol 'ana_fe_coeff_13seg' was not declared. Should it be static?

Cc: Patrick Boettcher <pboettcher@kernellabs.com>
Signed-off-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>