UBOOT: set provides/provides to 'u-boot'

This is required as some recipes might depend on the 'u-boot' recipe,
and if this is not present it would pull in the upstream recipe in
oe-core instead.

Change-Id: I0d5b19358aa7bc328b546f5fd2fec5d69a2456c4
Suggested-by: Mirza Krak <mirza.krak@northern.tech>
https: //github.com/STMicroelectronics/meta-st-stm32mp/pull/11/

recipes-bsp/u-boot/u-boot-stm32mp.inc

@@ -2,6 +2,9 @@ require recipes-bsp/u-boot/u-boot.inc
 
 FILESEXTRAPATHS_prepend := "${THISDIR}/u-boot-stm32mp:"
 
+PROVIDES += "u-boot"
+RPROVIDES_${PN} += "u-boot"
+
 # Configure build dir for externalsrc class usage through devtool
 EXTERNALSRC_BUILD_pn-${PN} = "${WORKDIR}/build"