misc: bh1770glc: remove unused array prox_curr_ma

Array prox_curr_ma is declared but never used, hence it is redundant
and can be removed.

Cleans up clang warning:
warning: 'prox_curr_ma' defined but not used [-Wunused-const-variable=]

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>