rtlwifi: Fix endian issue in ps.c

Sparse reports the following endian issues:

  CHECK   drivers/net/wireless/realtek/rtlwifi/ps.c
drivers/net/wireless/realtek/rtlwifi/ps.c:772:42: warning: restricted __le32 degrades to integer
drivers/net/wireless/realtek/rtlwifi/ps.c:772:42: warning: cast to restricted __le32
drivers/net/wireless/realtek/rtlwifi/ps.c:775:42: warning: restricted __le32 degrades to integer
drivers/net/wireless/realtek/rtlwifi/ps.c:775:42: warning: cast to restricted __le32
drivers/net/wireless/realtek/rtlwifi/ps.c:778:42: warning: restricted __le32 degrades to integer
drivers/net/wireless/realtek/rtlwifi/ps.c:778:42: warning: cast to restricted __le32
drivers/net/wireless/realtek/rtlwifi/ps.c:867:42: warning: restricted __le32 degrades to integer
drivers/net/wireless/realtek/rtlwifi/ps.c:867:42: warning: cast to restricted __le32
drivers/net/wireless/realtek/rtlwifi/ps.c:870:42: warning: restricted __le32 degrades to integer
drivers/net/wireless/realtek/rtlwifi/ps.c:870:42: warning: cast to restricted __le32
drivers/net/wireless/realtek/rtlwifi/ps.c:873:42: warning: restricted __le32 degrades to integer
drivers/net/wireless/realtek/rtlwifi/ps.c:873:42: warning: cast to restricted __le32

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200604005733.7905-2-Larry.Finger@lwfinger.net