omap: Fix warnings from Sparse

omap: Fix warnings from Sparse

Sparse report:

arm/omap1.c:1015:9: warning: returning void-valued expression
arm/omap1.c:1084:9: warning: returning void-valued expression
arm/omap1.c:1178:9: warning: returning void-valued expression
arm/omap1.c:1287:9: warning: returning void-valued expression
arm/omap1.c:1382:9: warning: returning void-valued expression
arm/omap1.c:1650:9: warning: returning void-valued expression
arm/omap1.c:1778:9: warning: returning void-valued expression
arm/omap1.c:1985:9: warning: returning void-valued expression
arm/omap1.c:210:9: warning: returning void-valued expression
arm/omap1.c:2213:9: warning: returning void-valued expression
arm/omap1.c:2352:9: warning: returning void-valued expression
arm/omap1.c:2447:9: warning: returning void-valued expression
arm/omap1.c:2640:9: warning: returning void-valued expression
arm/omap1.c:317:9: warning: returning void-valued expression
arm/omap1.c:3413:13: warning: returning void-valued expression
arm/omap1.c:3414:13: warning: returning void-valued expression
arm/omap1.c:3415:14: warning: returning void-valued expression
arm/omap1.c:3589:9: warning: returning void-valued expression
arm/omap1.c:443:9: warning: returning void-valued expression
arm/omap1.c:588:9: warning: returning void-valued expression
arm/omap1.c:860:9: warning: returning void-valued expression
arm/omap2.c:1362:9: warning: returning void-valued expression
arm/omap2.c:450:9: warning: returning void-valued expression
arm/omap2.c:695:9: warning: returning void-valued expression
arm/omap2.c:760:9: warning: returning void-valued expression
hw/char/omap_uart.c:115:9: warning: returning void-valued expression
hw/display/omap_dss.c:1019:9: warning: returning void-valued expression
hw/display/omap_dss.c:215:9: warning: returning void-valued expression
hw/display/omap_dss.c:380:9: warning: returning void-valued expression
hw/display/omap_dss.c:739:9: warning: returning void-valued expression
hw/display/omap_dss.c:931:9: warning: returning void-valued expression
hw/dma/omap_dma.c:139:5: warning: returning void-valued expression
hw/dma/omap_dma.c:1505:9: warning: returning void-valued expression
hw/dma/omap_dma.c:1860:9: warning: returning void-valued expression
hw/gpio/omap_gpio.c:116:9: warning: returning void-valued expression
hw/misc/omap_gpmc.c:627:9: warning: returning void-valued expression
hw/misc/omap_l4.c:85:9: warning: returning void-valued expression
hw/misc/omap_sdrc.c:95:9: warning: returning void-valued expression
hw/misc/omap_tap.c:98:9: warning: returning void-valued expression
hw/sd/omap_mmc.c:409:9: warning: returning void-valued expression
hw/ssi/omap_spi.c:229:9: warning: returning void-valued expression
hw/timer/omap_gptimer.c:447:9: warning: returning void-valued expression

Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>