Fix improper 'const' propagation

Fix improper 'const' propagation

It turns out that data 'data' points to
is always constant, so we can declare that
the pointer 'data' points to constant data
without problem.

drivers/net/wireless/iwlwifi/mvm/fw.c:90:64: warning:
initialization discards 'const' qualifier from
pointer target type [-Wdiscarded-array-qualifiers]
{.size = sizeof(_buf), .data = &_buf}
                                                                ^
drivers/net/wireless/iwlwifi/mvm/fw.c:93:8: note:
in expansion of macro 'CALIB_SIZE_N_DATA'
[9] = CALIB_SIZE_N_DATA(wkp_calib_values_tx_iq_skew),

drivers/net/wireless/iwlwifi/mvm/fw.c:90:64: warning:
initialization discards 'const' qualifier from
pointer target type [-Wdiscarded-array-qualifiers]

drivers/net/wireless/iwlwifi/mvm/fw.c:94:9: note:
in expansion of macro 'CALIB_SIZE_N_DATA'
[11] = CALIB_SIZE_N_DATA(wkp_calib_values_rx_iq_skew),

Bug 200187768

Change-Id: Ib1d0dbd3b44238feb39f54d1ebff00c2edd09254
Signed-off-by: Joe Korty <joe.korty@ccur.com>
Signed-off-by: Gaurav Singh <gaursingh@nvidia.com>
Reviewed-on: http://git-master/r/1163937
GVS: Gerrit_Virtual_Submit
Reviewed-by: Bibek Basu <bbasu@nvidia.com>