msm: ais: Handling bigger value than upper bound in msm_cpp_irq api

 In msm_cpp_irq function, tx_level is read using msm_carmera_io_r(),
 However, this value is never verified to lower than
 MSM_CPP_TX_FIFO_LEVEL (16), As tx_level is used as the upper bound
 for the following loop, any value bigger than 16 will result in a
 buffer overflow. Hence handling this case as error with error log.

Change-Id: I1a922b0c14bb1a79297e71a6e5dda476042b5414
Signed-off-by: Suprith Malligere Shankaregowda <supgow@codeaurora.org>